# F-test two-sample for variances online dating

The decision process will be the same as well: if the test statistic falls in the rejection region we will reject the null hypothesis; if the -value is less than the preset level of significance we will reject the null hypothesis.

The interpretation of an confidence intervals in support of the hypothesis decision will also be familiar: if the interval does not contain the null hypothesis value then reject the null hypothesis; if the interval contains the null hypothesis value then we will fail to reject the null hypothesis.

or "Are you sure you want to conduct a right-tailed test? Instead, the researcher is responsible for understanding and interpreting the results.

This becomes especially true in this lesson where one has to pay attention to any difference is calculated.

Next, one has to determine if the samples are independent samples or dependent samples in order to choose between a 2-sample test and the paired test.

We will start with comparing two independent population proportions, move to comparing two independent population means, from there to paired population means, and ending with the comparison of two independent population variances.

That is, one could fail to reject a null hypothesis concluding that the diet did not result in a significant weight loss, where instead, if the proper alternative would have been selected a rejection would have taken place and the diet would have shown a significant weight loss.

A seemingly small mistake that has big consequences!!

However, if you were to select the options of "Difference less than hypothesize difference" you would get a decision that conflicts with the the prior option.

The equality of variance between groups is one of the assumptions of ANOVA and linear regression. Sample file is based on Cont1bin1cat1, which is a simulated data with 150 cases and three variables: one continuous, one binary, and one categorical with three levels.

We will be using the continuous variable as the dependent variable, and the three-level categorical variable as the independent variable.

For example, imagine you are conducting a weight loss study where you compare starting weight of your subjects to the end weight.

In such a study if you calculate the difference as "Start Weight - End Weight" you would expect the difference to be greater than zero.