Class, there are several different tests explained in this week's readings. At first it might seem confusing which one of all the tests should be selected to solve a problem. The selection of test statistic depends on the following factors:

• what parameter are we evaluating (mean, standard deviation, proportion, ...)
• type of data (qualitative or quantitative)
• size of sample (N < 30, or N > 30)

For instance, if we're comparing the mean against a hypothesized value, the test statistic would be a z-test when the sample size is greater than 30, or a t-test if the sample size is less than 30.

Similarly, if we're comparing a proportion against a hypothesized value, the test statistic is always a z-test.

Class, this week's readings also cover the ANOVA test. What is an ANOVA test and when do we use it?