Ninety people with high cholesterol are randomly divided into three groups of thirty, and a different treatment program for decreasing cholesterol is assigned to each group. The response variable is the change in cholesterol level after two months of treatment. An analysis of variance will be used to compare the three treatments. What null hypothesis is tested by this F-test?
A) The sample variances are equal for the three treatment groups.
B) The population variances are equal for the three treatments.
C) The sample means are equal for the three treatment groups.
D) The population means are equal for the three treatments

Question

Quizplus · Accepted Answer

The null hypothesis tested by an F-test in an analysis of variance (ANOVA) is that the population means are equal across the groups. This means that any observed differences in sample means are attributed to random variation rather than differences in the effectiveness of the treatments.

Ninety People with High Cholesterol Are Randomly Divided into Three