Chapter 7.2, Problem 48E

Menopause in Mexico. In the article ‘‘Age at Menopause in Puebla, Mexico” (Human Biology, Vol. 75, No. 2, pp. 205–206), authors L. Sievert and S. Hautaniemi compared the age of menopause for different populations. Menopause, the last menstrual period, is a universal phenomenon among females. According to the article, the mean age of menopause, surgical or natural, in Puebla, Mexico is 44.8 years with a standard deviation of 5.87 years. Let $\bar{x}$ denote the mean age of menopause for a sample of females in Puebla, Mexico.

1. a. For samples of size 40, find the mean and standard deviation of $\bar{x}$. Interpret your results in words.
2. b. Repeat part (a) with n = 120.