The Body Mass Index (BMI) is a value calculated based on theweight and the height of an individual. In a small European city, asurvey was conducted one year ago to review the BMI of thecitizens. In the sample
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with 200 citizens, the mean BMI was 23.3 kg/m and standarddeviation was 1.5 kg/m . It is reasonable to
assume the BMI distribution is a normal distribution.
(a) Find the point estimate of the population mean BMI one yearago.
(b) Calculate the sampling error at 90% confidence.
(c) Construct a 90% confidence interval estimate of thepopulation mean BMI one year ago.
This city launched a healthy exercise program to reducecitizen’s BMI after last year’s survey.
program effectively reduces the BMI of each citizen by 2.5%.
(d) Construct a 98% confidence interval estimate of the populationmean BMI after the healthy exercise
program. (Hint: find the updated sample mean and sample standarddeviation of the BMI of the sample with 200 citizens selected lastyear)
