Stacy is preparing for a quiz in her statistics class. The quiz covers three kinds of statistical tests—t-tests for comparing whether the means of two groups are different (such as whether the students in Mr. A’s class get significantly better or worse grades on the final exam than students in Ms. B’s class), chi-square tests for comparing whether two groups differ in the proportions of some category (such as whether the proportion of girls and boys in Mr. A’s class is significantly different than the proportion of boys and girls in Ms. B’s class), and correlations for determining the relationship between two variables (such as determining whether student height in inches is significantly related to their grade on the final exam in Mr. A’s class).