Question

A researcher wishes to investigate the idea that eating salt raises blood pressure. She randomly selects two groups, one with 15 people and one with 13 people. She arranges that Group 1 (15 people) will be on a high sodium diet for 2 weeks, while Group 2 will be on a low sodium diet. She measures their blood pressure after the two weeks. The mean systolic blood pressure for Group 1 is found to be 120 with a sample standard deviation of 4, while for Group 2 it is found to be 114 with a sample standard deviation of 6. Which of the following statistical tests should she use to determine whether the difference is statistically significant?

Pooled t-test

b. Single sample z-test

c. Paired t-test

d. Two sample z-test

Answer 1