A Calculate and interpret a 99 CI for population mean backpa

A.) Calculate and interpret a 99% CI for population mean backpack weight.

B.) Obtain a 99% CI for population mena weight as a percentage of body weight.

C.) The American Academy of Orthopedic Surgeons recommends that backpack weight be at most 10% of body weight. What does your calculation of part (b) suggest and why?

Young people may feel they are carrying the weight of the world on their shoulders when in reality they are too often carrying an excessively heavy backpack. The article Effectiveness of a School-Based Backpack Health Promotion Program reported the following data for a smaple of 131 sixth graders: for backpack weight (lb) x = 13.83, s = 5.05 ; for backpack weight as a percentage of body weight, a 95% CI for the population mean was (13.62; 15.89) A.) Calculate and interpret a 99% CI for population mean backpack weight. B.) Obtain a 99% CI for population mena weight as a percentage of body weight. C.) The American Academy of Orthopedic Surgeons recommends that backpack weight be at most 10% of body weight. What does your calculation of part (b) suggest and why?

Solution

1) the confidence interval is

(12.6938, 14.9661)

b) using the given confidence interval we find mean value

13.62=mean-1.96*0.4412

mean= 14.48

the confidence interval is

(13.3438,15.6161)

c) Since the lower limit of the class interval is 15.61, it suggests that atleast the backpack weight sould be a most 10% of the body weight.