The diameter of a brand of tennis balls is approximately normally distributed, with a mean of

2.682.68

inches and a standard deviation of

0.030.03

inch. A random sample of

1111

tennis balls is selected. Complete parts (a) through (d) below.

a. What is the sampling distribution of the mean?

A.

Because the population diameter of tennis balls is approximately normally distributed, the sampling distribution of samples of size

will also be approximately normal.Your answer is correct.

B.

Because the population diameter of tennis balls is approximately normally distributed, the sampling distribution of samples of size 11

will be the uniform distribution.

C.

Because the population diameter of tennis balls is approximately normally distributed, the sampling distribution of samples of size

1111D.

Because the population diameter of tennis balls is approximately normally distributed, the sampling distribution of samples of size

11will not be approximately normal.

b. What is the probability that the sample mean is less than 2.65inches?

P(Upper X overbarXless than<2.65)equals=

(Round to four decimal places as needed.)