Statistics

• Students T-test is used to compare the means of two groups of continuous data
• There are two types of T-tests: independent samples t-test and paired samples t-test
• INDEPENDENT SAMPLES T-TEST:

  Compares the mean of two independent groups
• Paired Samples T-Test: Used when comparing two related sets of measurements from the same group of individuals or objects.
• To perform a T-test we...

  Calculate the T-statistic (measured by the difference between the sample means divided by the standard error of difference)

  Then compare the t-statistic to a critical value from the t-distribution table with degrees of freedom equal to the sample size minus 1.
• Chi Squared test is used to test the association between two categorical variables
• Chi Squared test compares observed frequencies with the expected frequencies under the null hypothesis
• The Chi Squared statistic is calculated by summing the squared difference between observed and expected frequencies divided by the expected value


  Then compared to a critical value from the chi squared distribution with degrees of freedom equal to the number of categories minus 1
• F-test is used to compare the variance of two or more groups of continuous data. It is typically used in ANOVA (analysis of variance) to test whether there is a significant difference between the means of two or more groups of data. The F-test calculates the ratio of variances between groups. The resulting F-statistic is compared to a critical value from the F-distribution with the degrees of freedom equal to number of groups minus 1 and total sample size minus number of groups