It has been postulated that a student is more likely to smokemarijuana if both parents use alcohol and drugs. A paper publishedin Youth and Society (1979) reported that among 570 students whoseparents use alcohol and drugs, 320 regularly smoke marijuana.
a. Is there any evidence that a student is more likelyto smoke marijuana if both parents use alcohol and drugs?
b. Joann is planning for a new study on this problem.Suppose no prior information is available, what is the minimumsample size required such that the length of the 92.32% confidenceinterval for the true proportion of students smoke marijuana ifboth parents use alcohol and drugs is at most 0.075?
