Question

in a study of 317,323 cell phone users, it was found that 116 developed cancer of the brain or nervous system. assuming that cell phones have no effect, there is a 0.000406 probability of a person developing cancer of the brain or nervous system. we therefore expect about 129 cases of such cancer in a group of 317,323 people. estimate the probability of 116 or fewer cases of such cancer in a group of 317,323 people. what do these results suggest about media reports that cell phones cause cancer of the brain or nervous system? (a) p(x ≤ 116) = 0.1448 (round to four decimal places as needed.) (b) what does the result from part (a) suggest about the media reports? a. the media reports appear to be correct because one would expect that less than 129 cell phone users would develop cancer and the study offers some evidence to support this. b. the media reports appear to be incorrect because one would expect that more than 129 cell phone users would develop cancer. in fact, the study may offer some evidence to suggest that cell phone use decreases the probability of developing cancer. c. the media reports appear to be correct because one would expect that more than 116 cell phone users would develop cancer and the study offers some evidence to support this.

Explanation:

Step1: Analyze probability result

We are given that $P(x\leq116) = 0.1448$. The expected number of cases is 129. Since 116 is less than 129 and the probability of having 116 or fewer cases is relatively low.

Step2: Evaluate media - reports

Media reports claim that cell - phones cause cancer. But the observed number of cases (116) is less than the expected number (129) assuming no effect from cell - phones.

Answer:

B. The media reports appear to be incorrect because one would expect that more than 129 cell phone users would develop cancer. In fact, the study may offer some evidence to suggest that cell phone use decreases the probability of developing cancer.