Question

A rare form of malignant tumor occurs in 11 children in a​ million, so its probability is 0.000011. Four cases of this tumor occurred in a certain​ town, which had

15915 children.

a. Assuming that this tumor occurs as​ usual, find the mean number of cases in groups of

15915 children.

b. Using the unrounded mean from part

​(a​),

find the probability that the number of tumor cases in a group of

15915

children is 0 or 1.

c. What is the probability of more than one​ case?

d. Does the cluster of four cases appear to be attributable to random​ chance? Why or why​ not?

a. The mean number of cases is

?

​(Type an integer or decimal rounded to three decimal places as​ needed.)

b. The probability that the number of cases is exactly 0 or 1 is

?

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

c. The probability of more than one case is

?

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

d. Let a probability of 0.05 or less be​ "very small," and let a probability of 0.95 or more be​ "very large". Does the cluster of four cases appear to be attributable to random​ chance? Why or why​ not?

A.

​No, because the probability of more than one case is very small.

Your answer is correct.

B.

​Yes, because the probability of more than one case is very small.

C.

​Yes, because the probability of more than one case is very large.

D.

​No, because the probability of more than one case is very large.

Answer 1