In Ventura County in 2013, it was thought that 40% of men 50 years old or older had never been screened for prostate cancer. Suppose a random sample of 80 of these men shows that 30 of them had never been screened.
a. What is the observed frequency of men who said they had not been screened?
b. What is the observed proportion of men who said they had not been screened?
c. What is the expected number in the sample to say they had never been screened if 40% is the correct rate?