Many researchers believe moderate physical activity, such as walking, will help prevent weight gain. To study this claim, doctors in Colorado had randomly selected patients wear a pedometer to measure...

Many researchers believe moderate physical activity, such as walking, will help prevent weight gain. To study this claim, doctors in Colorado had randomly selected patients wear a pedometer to measure the distance walked (in miles) per week. The table below presents data for men and women.

a. Find a 95% confidence interval for the true variance in distance walked per week for men.

b. Find a 95% confidence interval for the true variance in distance walked per week for women.

 c. Is there any evidence to suggest the true variance is different for men and women? Justify your answer.

 d. What assumption(s) did you make in constructing the confidence intervals above?