Forty-two percent of primary care doctors think their patients receive unnecessary medical care (Reader's Digest, December 2011 /January 201 2).
a. Suppose a sample of 300 primary care doctors were taken. Show the sampling distribution of the proportion of the doctors who think their patients receive unnecessary medical care.
b. What is the probability that the sample proportion will be within -/+ .03 of the population proportion?
c. What is the probability that the sample proportion will be within -/+ .05 of the popula-tion proportion?
d. What would be the effect of taking a larger sample on the probabilities in parts (b) and (c)? Why?