Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

Pinworm: In Sludge County, a sample of 50 randomly selected citizens were tested

ID: 3180613 • Letter: P

Question

Pinworm: In Sludge County, a sample of 50 randomly selected citizens were tested for pinworm. Of these, 9 tested positive. The CDC reports that the U.S. average pinworm infection rate is 12%. Test the claim that Sludge County has a pinworm infection rate that is greater than the national average. Use a 0.05 significance level.

reject H0

fail to reject H0    


(e) Choose the appropriate concluding statement.

The data supports the claim that the infestation rate in Sludge County is greater than the national average.

There is not enough data to support the claim that that the infestation rate in Sludge County is greater than the national average.    

We reject the claim that the infestation rate in Sludge County is greater than the national average.

We have proven that the infestation rate in Sludge County is greater than the national average.

Explanation / Answer

a) point estimate =phat =9/50 =0.18

b)std error =(p(1-p)/50)1/2  where p=0.12

=0.046

hence zstat =(phat-p)/std error =1.3056

c) p value =0.0958

d) fail to reject Ho

e)There is not enough data to support the claim that that the infestation rate in Sludge County is greater than the national average.