Question

n a study of

248 comma ,648

cell phone​ users, it was found that

68

developed cancer of the brain or nervous system. Assuming that cell phones have no​ effect, there is a

.000281 probability of a person developing cancer of the brain or nervous system. We therefore expect about

70

cases of such cancer in a group of

248 comma ,648

people. Estimate the probability of

68

or fewer cases of such cancer in a group of

248 comma ,648

people. What do these results suggest about media reports that cell phones cause cancer of the brain or nervous​ system?

​(a)

​P(xless than or equals≤68​)equals=nothing

​(Round to four decimal places as​ needed.)

Answer 1

a) P(x < 68)

= P(p < 68/248648)

= P(z < -0.22)

= 0.4115