Article on Roger Clemens' and Barry Bonds' performance ** Super-Angebote für Student And Home 2010 hier im Preisvergleich bei Preis**.de T-Test Calculator for 2 Independent Means. This simple t-test calculator, provides full details of the t-test calculation, including sample mean, sum of squares and standard deviation. T-Test Calculator. Further Information. A t-test is used when you're looking at a numerical variable - for example, height - and then comparing the averages of two separate populations or groups (e.g., males and.

- The t test compares one variable (perhaps blood pressure) between two groups. Use correlation and regression to see how two variables (perhaps blood pressure and heart rate) vary together. Also don't confuse t tests with ANOVA. The t tests (and related nonparametric tests) compare exactly two groups. ANOVA (and related nonparametric tests.
- Our Student's t-test calculator can do one sample t tests, two sample paired t-tests and two sample unpaired t-tests. Results page will give you t-Score, standard error of difference, degrees of freedom, two-tailed p-value, mean difference and confidence range. You can choose the confidence interval
- e if means of two data sets differ significantly. This calculator will generate a step by step explanation on how to apply t - test. Two sample t-test One sample t-test. Two sample t-test calculator. One or two tails, equal or unequal variances, paired or unpaired + steps. show help ↓↓ examples ↓↓., Enter Data for Group 1. Enter Data for Group 2.
- Student t-Value Calculator. In order to calculate the Student T Value for any degrees of freedom and given probability. The calculator will return Student T Values for one tail (right) and two tailed probabilities. Please input degrees of freedom and probability level and then click CALCULAT
- T-Test Calculator for 2 Independent Means. Note: You can find further information about this calculator, here. Enter the values for your two treatment conditions into the text boxes below, either one score per line or as a comma delimited list. Select your significance level and whether your hypothesis is one or two-tailed. Then give your data a final check, and press the Calculate T and P.
- You can use this T-Value Calculator to calculate the Student's t-value based on the significance level and the degrees of freedom in the standard deviation. How to use the calculator. Enter the degrees of freedom (df) Enter the significance level alpha (α is a number between 0 and 1

This test is run to check the validity of a null hypothesis based on the critical value at a given confidence interval and degree of freedom. However, please note that the student's t-test is applicable for data set with a sample size of less than 30. t-Test Formula Calculator. You can use the following t-Test Formula Calculato The paired **t** **test** tool calculates p-value, power, effect. Find outlietrs. Draw distribution chart and a histogram. The **test** uses **T** distribution . Paired **T-Test** Calculator. Dependent **T** **test**. Video Information **T** equal σ calculator **T** unequal σ calculator. **Test** **calculation**. If you enter raw data, the tool will run the Shapiro-Wilk normality **test** and calculate outliers, as part of the paired-t. ** T-Test verstehen und interpretieren**. Veröffentlicht am 2. April 2019 von Priska Flandorfer. Aktualisiert am 20. August 2020. Den t-Test, auch als Students t-Test bezeichnet, verwendest du, wenn du die Mittelwerte von maximal 2 Gruppen miteinander vergleichen möchtest.. Zum Beispiel kannst du mit dem t-Test analysieren, ob Männer im Durchschnitt größer als Frauen sind Student's t-test calculator for test of significance (hypothesis) for single mean, difference between two means & two equal sample size s (paired t-test) by using t-statistic (t 0) & critical value of t (t e) for small samples of population in statistical surveys & experiments Data Entry: Student's t-test You are about to enter two sets of data so that Student's t-test can be used to determine if the averages of your two samples are significantly different. For each dataset, enter your data into the given box separating each datum from its neighbor with tabs, commas, or spaces. Very commonly you will already have the data in your computer in some format. You should.

T-test online. To compare the difference between two means, two averages, two proportions or two counted numbers. The means are from two independent sample or from two groups in the same sample. A number of additional statistics for comparing two groups are further presented. Including number needed to treat (NNT), confidence intervals, chi-square analysis A-priori Sample Size Calculator for Student t-Tests. This calculator will tell you the minimum required total sample size and per-group sample size for a one-tailed or two-tailed t-test study, given the probability level, the anticipated effect size, and the desired statistical power level. Please enter the necessary parameter values, and then click 'Calculate'. Anticipated effect size (Cohen. p-Value Calculator for a Student t-Test This calculator will tell you the one-tailed and two-tailed probability values of a t-test, given the t-value and the degrees of freedom. Please enter the necessary parameter values, and then click 'Calculate' This test, also known as Welch's t-test, is used only when the two population variances are not assumed to be equal (the two sample sizes may or may not be equal) and hence must be estimated separately.The t statistic to test whether the population means are different is calculated as: = ¯ − ¯ ¯ where ¯ = +. Here s i 2 is the unbiased estimator of the variance of each of the two samples.

Learn using step-by-step techniques to calculate the t statistic when comparing dependent/paired samples. This video uses pre-test and post-test scores to ch.. Then, we enter the t statistic (-0.4276) and the degrees of freedom (13) into the calculator, and hit the Calculate button. The calculator reports that the cumulative probability is 0.338. Therefore, there is a 33.8% chance that the average breaking strength in the test will be no more than 19,800 pounds * Student's t-test is a parametric test as the formula depends on the mean and the standard deviation of the data being compared*. Note that an online t-test calculator is available here to compute t-test statistics without any installation. Related Book: Practical Statistics in R for Comparing Groups: Numerical Variables One-sample t-test formula. As mentioned above, one-sample t-test is used. The calculator to perform t-Test for the Significance of the Difference between the Means of Two Independent Samples. person_outlineTimurschedule 2018-08-05 07:09:59. The calculator below implements most known statistical test, namely, Independent Samples t-test or Two samples t-test. t-test also known as Student's t-test, after William Sealy Gosset. Student was his pen name. The test deals. Any field that does not have a value in the x or y fields will be ignored. As many as 100 paired data samples can be entered into this calculator. To use our paired t-test calculator if you want to calculate the test statistic of paired data samples, see our paired t-test calculator. Related Resource

Test the mean difference between two samples of continuous data using the 2-sample t-test. The calculator uses the probabilities from the student t distribution. For all t-tests see the easyT Excel Calculator : : Sample data is available. Fore more information on 2-Sample t-tests View the Comparing Two Means: 2 Sample t-test tutoria Student's t-test, in statistics, a method of testing hypotheses about the mean of a small sample drawn from a normally distributed population when the population standard deviation is unknown.. In 1908 William Sealy Gosset, an Englishman publishing under the pseudonym Student, developed the t-test and t distribution. (Gosset worked at the Guinness brewery in Dublin and found that existing. The calculation of student's t distribution is quite simple, but yes, the values are required. For example, one needs the population mean, which is the universe means, which is nothing but the average of the population whereas sample mean is required to test the authenticity of the population mean whether the statement claimed on the basis of population is indeed true and sample if any taken.

Conclusion: We do a two-tail test (inequality). lf t Stat < -t Critical two-tail or t Stat > t Critical two-tail, we reject the null hypothesis. This is not the case, -2.365 < 1.473 < 2.365. Therefore, we do not reject the null hypothesis. The observed difference between the sample means (33 - 24.8) is not convincing enough to say that the average number of study hours between female and male. Le test-t de Student comparant deux groupes d'échantillons dépendants (on parle de test de Student appari é). Cet article a pour objectif de décrire les formules pour les différents types de test de Student. Le test de Student est dit paramétrique car, comme nous allons le voir, la formule dépend de la moyenne et de l'écart-type des observations à comparer. Noter qu'un logiciel. An introduction to t-tests. Published on January 31, 2020 by Rebecca Bevans. Revised on October 12, 2020. A t-test is a statistical test that is used to compare the means of two groups. It is often used in hypothesis testing to determine whether a process or treatment actually has an effect on the population of interest, or whether two groups are different from one another The Student's t-test is a statistical test that compares the mean and standard deviation of two samples to see if there is a significant difference between them. In an experiment, a t-test might be used to calculate whether or not differences seen between the control and each experimental group are a factor of the manipulated variable or simply the result of chance. The unpaired T-test would. Die studentsche t-Verteilung (auch Student-t-Verteilung oder kurz t-Verteilung) ist eine Wahrscheinlichkeitsverteilung, die 1908 von William Sealy Gosset entwickelt und nach seinem Pseudonym Student benannt wurde.. Gosset hatte festgestellt, dass die standardisierte Schätzfunktion des Stichproben-Mittelwerts normalverteilter Daten nicht mehr normalverteilt, sondern -verteilt ist, wenn die zur.

Die Telekom ist zweifelsohne ein interessanter Arbeitgeber. Damit dieser auch eine sinnvolle Auswahl unter allen Bewerbern vornehmen kann, fordert die Telekom einen Einstellungstest, den du online durchführen kannst. Dieser Test wird von allen gefordert, die sich auf einen Ausbildungsplatz oder ein duales Studium bei der Telekom bewerben ** Da der Student-T Test einen Mittelwelt aus den jeweiligen Gruppen bildet, macht es keinen Sinn die obige Formel zu benutzen, oder? Viele Grüße Thomas**. Antworten. Michaela sagt: Mai 22, 2018 um 11:17 am Uhr Hallo, welche Formel wird für die Berechnung des T-Tests genutzt? Vielen Dank! Antworten. Schreibe einen Kommentar Antworten abbrechen. Deine E-Mail-Adresse wird nicht veröffentlicht. Online calculator. Calculates cumulative distribution function value and probability density function value for Student t-distribution. Quantile calculator evaluates Student quantiles for given probability and specified number of degrees of freedom How to use this t-test calculator for One Sample. More about the t-test for one mean so you can better interpret the results obtained by this solver: A t-test for one mean is a hypothesis test that attempts to make a claim about the population mean (\(\sigma\)). This t-test, unlike the z-test, does not need to know the population standard deviation \(\sigma\) Student's t-Tests Student (real name: W. S. Gossett [1876-1937]) developed statistical methods to solve problems stemming from his employment in a brewery. Student's t-test deals with the problems associated with inference based on small samples: the calculated mean (X avg) and standard deviation () may by chance deviate from the real mean and standard deviation (i.e., what you'd measure.

- Alternative zu Statistik Software wie SPSS und SAS DATAtab wurde von Grund auf für eine einfache Bedienung entwickelt und ist eine überzeugende kostenlose alternative zu Statistikprogrammen wie SPSS und SAS. Auf datatab.de können direkt online und sehr einfach Daten statistisch ausgewertet werden (z.B. t-Test, Regression, Korrelation etc.)
- Die Freiheitsgrade des Zweistichproben-t-Test für unabhängige Stichproben sind n 1 + n 2 − 2.. Da die Stichprobengröße verwendet wird, um den Standardfehler zu schätzen, müssen wir noch einen Korrekturfaktor einfügen. Die Gleichung muss angepasst werden, um zu berücksichtigen, dass die Größe beider Stichproben nicht gleich sein muss
- e if two sets of data are significantly different from each other, and is most commonly applied when the test statistic would follow a normal distribution if the value of a scaling term in the test statistic were known
- (Calculation according to Eid et al., 2011, S. 548 f.; single sided testing) 3. Testing linear independence (Testing against 0) With the following calculator, you can test if correlations are different from zero. The test is based on the Student's t distribution with n - 2 degrees of freedom. An example: The length of the left foot and the nose.

2 Sided Test Enter a value for α (default is .05): Enter a value for desired power (default is .80): The sample size (for each sample separately) is: Reference: The calculations are the customary ones based on normal distributions. See for example Hypothesis Testing: Two-Sample Inference - Estimation of Sample Size and Power for Comparing Two Means in Bernard Rosner's Fundamentals of. Calculates the probability density function and lower and upper cumulative distribution functions of the student's t-distribution. percentile x : degree of freedom ν: ν＞0; Customer Voice. Questionnaire. FAQ. Student's t-distribution [1-2] /2: Disp-Num [1] 2017/10/15 05:47 Female / 40 years old level / High-school/ University/ Grad student / Very / Purpose of use check I obtained the value.

Calculate s d (the square root of s d 2) 7. Calculate the t value as follows: (when doing this, transpose 1 and 2 if 2 > 1 so that you always get a positive value) 8. Enter the t-table at (n 1 + n 2-2) degrees of freedom; choose the level of significance required (normally p = 0.05) and read the tabulated t value. 9. If the calculated t value exceeds the tabulated value we say that the means. **T-Test** Calculator is a free **online** tool that displays the **T-test** value along with the mean and standard deviation for the two sets of data. BYJU'S **online** **T-test** calculator tool makes the **calculation** faster and it displays the **t-test** value in a fraction of seconds. How to Use the **T-Test** Calculator In probability and statistics, T distribution can also be referred as Student's T Distribution. It is very similar to the normal distribution and used when there was only small number of samples. The larger the sample size, the higher the 't' distribution looks like a normal distribution. The critical values of 't' distribution are calculated according to the probabilities of two alpha. Perhaps one of the most widely used statistical hypothesis tests is the Student's t test. Because you may use this test yourself someday, it is important to have a deep understanding of how the test works. As a developer, this understanding is best achieved by implementing the hypothesis test yourself from scratch. In this tutorial, you will discover how to implement th How to Conduct a Two-Sample T-Test (T-Test Calculator Explanation Included) There are 4 steps to conducting a two-sample t-test: 1. Calculate the t-statistic. As could be seen above, each of the 3 types of t-test has a different equation for calculating the t-statistic value. Here's the formula for a two-sample t-test

A one sample t test compares the mean with a hypothetical value. In most cases, the hypothetical value comes from theory. For example, if you express your data as 'percent of control', you can test whether the average differs significantly from 100. The hypothetical value can also come from previous data. For example, compare whether the mean systolic blood pressure differs from 135, a value. Calculate the p value (how likely it is that random fluctuations alone could produce a t value at least as large as the value you just calculated) using the Student t distribution. The Student t statistic is always calculated as D / SE ; each kind of t test (one-group, paired, unpaired, Welch) calculates D , SE, and df in a way that makes sense for that kind of comparison, as summarized here

- g a T-test, it means that you're attempting to obtain evidence of a significant variation between a hypothesized value and a population means or between two population means. In statistics, you use the T value or T score to measure how big the difference is in relation to the variation in your data sample. In other words, the T score is the difference which you've calculated.
- g it to the common form for comparison of scores
- The logic and computational details of two-sample t-tests are described in Chapters 9-12 of the online text Concepts & Applications of Inferential Statistics. For the independent-samples t-test, this unit will perform both the usual t-test, which assumes that the two samples have equal variances, and the alternative t-test, which assumes that the two samples have unequal variances
- T-Test: This test is most commonly applied when the test statistic would follow a normal distribution if the value of a scaling term in the test statistic were known. When the scaling term is unknown and is replaced by an estimate based on the data, the test statistic (under certain conditions) follows a Students t distribution
- g Unequal Variances data analysis tool to get.
- The significance level, or P-value, is calculated using the t-test, with the value t calculated as: The P-value is the area of the t distribution with n 1 + n 2 − 2 degrees of freedom, that falls outside ± t (see Values of the t distribution table). When the P-value is less than 0.05 (P<0.05), the conclusion is that the two means are significantly different. Note that in MedCalc P-values.

Student t-test 1. Student t-test Unit 8 strand 2. Student‟s t-test Student was W. S. Gossett. He published his test anonymously as Student‟ because he was working for the brewer‟s Guinness and had to keep the fact they were suing statistics a secre Save Page to: Inverse t-Distribution Calculator View all Calculators Calculates the critical value from the student t distribution given a proportion of area and degrees of freedom. Proportion of Are

- If you have prior reason to suspect that group 1 should have less effect than group 2, you can use a one-sided T-test, which has more power. **Warning**: you can't decide you want a one-sided T-test just because it has more power. You have to have a convincing reason why the difference should only be in one direction. ```{r} t.test(extra ~ group, data = sleep, alternative = less) ``` The.
- In statistics, the t-distribution was first derived as a posterior distribution in 1876 by Helmert and Lüroth. The t-distribution also appeared in a more general form as Pearson Type IV distribution in Karl Pearson's 1895 paper.. In the English-language literature the distribution takes its name from William Sealy Gosset's 1908 paper in Biometrika under the pseudonym Student
- The T-test for Two Independent Samples. More about the t-test for two means so you can better interpret the output presented above: A t-test for two means with unknown population variances and two independent samples is a hypothesis test that attempts to make a claim about the population means (\(\mu_1\) and \(\mu_2\)).. More specifically, a t-test uses sample information to assess how.
- e if a new teaching method has really helped teach a group of kids better, or if that group is just more intelligent
- It is known that under the null hypothesis, we can calculate a t-statistic that will follow a t-distribution with n1 + n2 - 2 degrees of freedom. There is also a widely used modification of the t-test, known as Welch's t-test that adjusts the number of degrees of freedom when the variances are thought not to be equal to each other. Before we can explore the test much further, we need to find.
- g that all of our conditions for inference are met. And then we wanna calculate a T statistic based on this sample data that we have. And our T statistic is going to be equal to the differences between the sample means, all of that over our estimate of the standard.
- Excel file: https://dl.dropboxusercontent.com/u/561402/TTEST.xls In this video Paul Andersen explains how to run the student's t-test on a set of data. He st..

Paired Sample t Test Example • Step 3: Determine Critical Cutoff • df = N-1 = 6-1= 5 • t statistic for 5 df , p < .05, two-tailed, are -2.571 and 2.571 • Step 5: Calculate t Statistic • Step 6 Decide 18.04 438.333 ( ) (7914.333 0) D D D SE M t The T-Test formula in excel used is as follows: =TTEST(A4:A24,B4:B24,1,1) The output will be 0.177639611.. T-TEST in Excel Example #2. A marketing research firm tests the effectiveness of a new flavoring for a leading beverage using a sample of 21 people, half of whom taste the beverage with the old flavoring and the other half who taste the beverage with the new flavoring Depending on the t-test and how you configure it, the test can determine whether: Two group means are different. Paired means are different. One mean is different from a target value. For more information about the types of t-tests you can use, read my post about 1-sample, 2-sample, and Paired t-Tests. Install the Data Analysis ToolPak in Exce

Calculate the T-test for the means of two independent samples of scores. This is a two-sided test for the null hypothesis that 2 independent samples have identical average (expected) values. This test assumes that the populations have identical variances by default. Parameters a, b array_like. The arrays must have the same shape, except in the dimension corresponding to axis (the first, by. Standard deviation: hypothesized standard deviation of differences (known for example from a Paired samples t-test from previous studies, or from the literature). Example You consider an average difference between two paired observations before and after a study, of at least 8 to be meaningful x: a (non-empty) numeric vector of data values. y: an optional (non-empty) numeric vector of data values. alternative: a character string specifying the alternative hypothesis, must be one of two.sided (default), greater or less.You can specify just the initial letter Beta is directly related to study power (Power = 1 - β). Most medical literature uses a beta cut-off of 20% (0.2) -- indicating a 20% chance that a significant difference is missed. Post-Hoc Power Analysis. To calculate the post-hoc statistical power of an existing trial, please visit the post-hoc power analysis calculator

I'd like to generate the t-test on it, but was wondering if there was an easy way to do this with numpy/scipy. Are there any good explanations around? For example, I have three related datasets that look like this: [55.0, 55.0, 47.0, 47.0, 55.0, 55.0, 55.0, 63.0] Now, I would like to do the student's t-test on them I created an Excel spreadsheet that automatically calculates t tests. If you need instructions on how to use the spreadsheet, watch this PowerPoint tutorial. Some content on this website may require the use of a plug-in, such as Microsoft Excel or Microsoft PowerPoint Visual, interactive two-sample t-test for comparing the means of two groups of data. Evan's Awesome A/B Tools : Sample Size Calculator | Chi-Squared Test | Sequential Sampling | 2 Sample T-Test | Survival Times | Count Data. Question: Does the average value differ. Using the t-Distribution to Calculate Confidence Intervals. By Consumer Dummies . Use the t-table as needed and the following information to solve the following problems: The mean length for the population of all screws being produced by a certain factory is targeted to be. Assume that you don't know what the population standard deviation is. You draw a sample of 30 screws and calculate. Variations of the t-Test: 2 Sample 2 tail 6 MINITAB output lets us know that MINITAB probably used only one or two more decimal places. The tSTAT in the output (T) is -5.18, the exact value we got manually indicating that our calculation of the Satterthwaite approximation was good, and as we expected, the p value is highly significant, therefore as p < a we reject the null hypothesis in.

Assuming unequal variances, the test statistic is calculated as: - where x bar 1 and x bar 2 are the sample means, s² is the sample variance, n 1 and n 2 are the sample sizes, d is the Behrens-Welch test statistic evaluated as a Student t quantile with df freedom using Satterthwaite's approximation. Note that is often more robust to use the nonparametric Mann-Whitney test as an alternative. This is more of a study design issue than something you can test for, but it is an important assumption of the independent t-test. If your study fails this assumption, you will need to use another statistical test instead of the independent t-test (e.g., a paired-samples t-test). If you are unsure whether your study meets this assumption, you can use ou T-tests are statistical hypothesis tests that you use to analyze one or two sample means. Depending on the t-test that you use, you can compare a sample mean to a hypothesized value, the means of two independent samples, or the difference between paired samples. In this post, I show you how t-tests use t-values and t-distributions to calculate probabilities and test hypotheses The t-test is any statistical hypothesis test in which the test statistic follows a Student's t-distribution under the null hypothesis.. A t-test is the most commonly applied when the test statistic would follow a normal distribution if the value of a scaling term in the test statistic were known. When the scaling term is unknown and is replaced by an estimate based on the data, the test.

Hypothesis test calculator t-test calculator, chi-squared calculator, ANOVA, binominal test . DATAtab allows you to perform hypothesis testing quickly and easily. Thanks to DATAtab's Auto-Assistant, you will be optimally supported in the test selection process and can quickly and easily select and execute the appropriate methods for testing your research hypotheses Computes p-values and t-values for Student's t-distributions. StatDistributions.com - Student's t-distribution calculator Enter either the p-value (represented by the blue area on the graph) or the test statistic (the coordinate along the horizontal axis) below to have the other value computed Better instructions will be placed here at a later date. For now, here are some from the Excel Help menu. t test Returns the probability associated with a Student's t-Test. Use TTEST to determine whether two samples are likely to have come from the same two underlying populations that have. Cohen's d for Student t-test. There are multiple version of Cohen's d for Student t-test. The most commonly used version of the Student t-test effect size, comparing two groups (\(A\) and \(B\)), is calculated by dividing the mean difference between the groups by the pooled standard deviation.Cohen's d formula Alternative Begriffe: Student-t-Test. Beispiel: t-Test. Beispiel für Einstichproben-t-Test. In einer Molkerei werden 1-Liter-Milchflaschen abgefüllt. Es wird eine Normalverteilung derart angenommen, dass die Milchflaschen mit 1 Liter gefüllt sind, kleinere Abweichungen (z.B. um 0,01 l auf 1,01 l) kommen öfters vor, größere (z.B. um -0,05 l auf 0,95 l) weniger oft. Es wird eine Stichprobe.

While working for the Guinness brewery in Ireland to evaluate the quality of ingredients used to make beer, he introduced a mathematical test known as the Student's t-test in 1908. Today, the t-test is being applied in modern finance to determine if a series of historical returns is reliably superior -- i.e., showing a t-statistic of 2 or higher -- to a risk-equivalent benchmark T-Test in Excel nutzen - so klappt's. Mit dieser Funktion können Sie in Excel prüfen, ob zwei Stichproben aus zwei Grundgesamtheiten mit demselben Mittelwert stammen: Die Grundformel lautet: TTEST(Matrix1;Matrix2;Seiten;Typ). Kopieren Sie diese in ein beliebiges Feld Ihres Excel-Dokuments. Als Matrix1 wird das erste Dataset bezeichnet, Matrix2 bezeichnet dementsprechend das zweite.

Calculate the test statistic that should be used for testing a null hypothesis that the population slope is actually zero. So pause this video and have a go at it. All right, so let's just make sure we understand what is going on. So let's first think about the population. So I'll do that right over here. So in the population, there might be some true linear relationships. So in theory, on our. The t-statistic is distributed on a curve that is based on the number of degrees of freedom (df), which, in the case of an Independent-Samples T-test is df = N1+N2-2. For other kinds of t-tests. Effect sizes can be obtained by using the tests statistics from hypothesis tests, like Student t tests, as well. In case of independent samples, the result is essentially the same as in effect size calculation #2. Dependent testing usually yields a higher power, because the interconnection between data points of different measurements are kept. This may be relevant f. e. when testing the same. Der t-Test ist ein Begriff aus der mathematischen Statistik, er bezeichnet eine Gruppe von Hypothesentests mit t-verteilter Testprüfgröße.Oft ist jedoch mit dem t-Test der Einstichproben- bzw. Zweistichproben-t-Test auf einen Mittelwertunterschied gemeint.Der Einstichproben-t-Test (auch Einfacher t-Test; engl. one-sample t-test) prüft anhand des Mittelwertes einer Stichprobe, ob der. The results for the two-sample t-test that assumes equal variances are the same as our calculations earlier. The test statistic is 2.79996. The software shows results for a two-sided test and for one-sided tests. The two-sided test is what we want (Prob > |t|). Our null hypothesis is that the mean body fat for men and women is equal. Our alternative hypothesis is that the mean body fat is not. Example: suppose that a t-test on a sample of 10 individuals (d.f. = 9) produced a t-value of 3.0.The table tells us that p is between 0.01 and 0.05 in this case (p=0.05 when t=2.26, and p=0.01 when t=3.25; our t-value lies in between these two).Therefore, the probability of the result arising by chance is less than 5% (p<0.05), so this is a fairly significant result