7.5. The National Center for Health Statistics recently estimated thatthe mean weight for adult American women was 140 pounds in 1962 and 164 pounds in 2002.

(a) Suppose these estimates had standard errors of 2 pounds each year. Estimate the increase in mean weight in the population from 1962 to 2002, and find and interpret the standard error of that estimate.

(b) Show thatthe estimated mean in 2002 was 1.17 times the estimated mean in 1962. Express this in terms ofthe percentage increase.

(c) The estimated mean weights for men were 166 pounds in 1962 and 191 in 2002. Find and interpret the difference and the ratio.