Question #9

Assume that females have pulse rates that are normally distributed with a mean of ?=73.0

beats per minute and a standard deviation of ?=12.5 beats per minute. Complete parts? (a) through? (c) below.

a. If 1 adult female is randomly? selected, find the probability that her pulse rate is less than

77 beats per minute.

The probability is __________.

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

b. If 4 adult females are randomly? selected, find the probability that they have pulse rates with a mean less than 77 beats per minute.

The probability is ____________.

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

c. Why can the normal distribution be used in part? (b), even though the sample size does not exceed? 30?

A. Since the distribution is of sample? means, not? individuals, the distribution is a normal distribution for any sample size.

B. Since the original population has a normal? distribution, the distribution of sample means is a normal distribution for any sample size.

C. Since the mean pulse rate exceeds? 30, the distribution of sample means is a normal distribution for any sample size.

D. Since the distribution is of? individuals, not sample? means, the distribution is a normal distribution for any sample size.

Question #10

Find the critical value z_?/2 that corresponds to the given confidence level.

98?%

z_?/2= __________

?(Round to two decimal places as? needed.)

Question #11

Express the confidence interval ( 0.039, 0.091 ) in the form of p?E

Express the confidence interval (0.039,0.091) in the form of p - E