3. A medical statistician wants to estimate average weight loss of people who are on a new diet plan. In a preliminary study, he guesses that the standard deviation of the population of weight losses...

3. A medical statistician wants to estimate average weight loss of people who are on a

new diet plan. In a preliminary study, he guesses that the standard deviation of the

population of weight losses σ is about 10 pounds. How large a sample should he take to

estimate the mean weight loss to within 2 pounds with 95% confidence?