Forty-two percent of primary care doctors think their patients receive unnecessary medical care (reader’s digest, December 2011/January 2012). a. Suppose a sample of 300 primary care doctors were...

Forty-two percent of primary care doctors think their patients receive unnecessary medical
care (reader’s digest, December 2011/January 2012).
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 population proportion?
d. What would be the effect of taking a larger sample on the probabilities in parts (b)
and (c)? Why?