Question

a health researcher was interested in finding out whether the dash diet can lower a dieters blood pressure. researchers compared the blood pressure before going on the diet with the same subjects blood pressure after 12 weeks on the dash diet. which of the following is the most appropriate statistical test to use to test whether the dash diet lowers blood pressure? a. matched pairs t - test b. two - sample t - test c. chi - squared test for independence d. anova e. inference for regression

Explanation:

• Matched pairs t - test:
• This test is used when we have two related samples (in this case, the same subjects' blood pressure before and after the diet).
• It accounts for the individual differences among subjects by looking at the differences within each pair (before - after for each person).
• Two - sample t - test:
• This is for two independent samples. Here, the samples (before and after) are not independent as they come from the same group of people.
• Chi - squared test for independence:
• Used to test if two categorical variables are independent. Blood pressure (a numerical variable, even if categorized as high/normal/low in some cases, but here we are comparing actual values) and diet (a treatment) do not fit the categorical - independence scenario for this test.
• ANOVA (Analysis of Variance):
• Used to compare means of three or more groups. Here we have only two related groups (before and after).
• Inference for regression:
• Used to study the relationship between a dependent variable and one or more independent variables in a linear relationship. The goal here is not to model a linear relationship between variables but to test for a mean difference in a paired - data (before - after) context.

Answer:

A. Matched pairs t - test