Question

In a certain county in​ 2013, it was thought that​ 50% of men 50 years old or older had never been screened for prostate cancer. Suppose a random sample of 200 of these men shows that 120 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​ 50% is the correct​ rate?

Answer 1

120,0.60,100

Explanation:

Given that in a certain county in​ 2013, it was thought that​ 50% of men 50 years old or older had never been screened for prostate cancer.

Suppose a random sample of 200 of these men shows that 120 of them had never been screened.

a) the observed frequency = 120

b) The observed proportion of men who said they had not been​ screened

=
`(120)/(200) \\=0.60`

c) Expected number in the sample to say they had never been screened if​ 50% is the correct​ rate

= np

=
`200*0.50=100`