題組內容

3. (20%) From a large population of residential water meters, a random sample of 360 meters is to be selected to estimate the proportion due for replacement within the next five years. Suppose that p = 0.40.

(b) (10%) Using a normal approximation, find the probability that (1)is less than 0.35；(2) lies within ±0.05 of the population proportion p.