Assume that females have pulse rates that are normally distributed with a mean of p = 76.0 beats per minute and a standard deviation of o = 125 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 80 beats per minute.
The probability is a
(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 80 beats per
minute
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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?
O A. Since the distribution is of individuals, not sample means, the distribution is a normal distribution for any sample size
OB. Since the original population has a normal distribution, the distribution of sample means is a normal distribution for any
sample size
O C. Since the mean pulse rate exceeds 30, the distribution of sample means is a normal distribution for any sample size
OD. Since the distribution is of sample means, not individuals, the distribution is a normal distribution for any sample size.