In Exercises, assume that red blood cell counts of women are normally distributed with a mean of 4.577 and a standard deviation of 0.382.

If 25 women are randomly selected, find the probability that the mean of their red blood cell counts is less than 4.444.

## Problem 9CQQ

Answer:

Step1 of 3:

We have red blood cell counts of women are normally distributed with a mean of 4.577 and a standard deviation of 0.382.

Step2 of 3:

We need to find the probability that the mean of their red blood cell counts is less than 4.444.

If 25 women are randomly selected.

Step3 of 3:

We have

Consider the z statistics with x = 4.444

P()

=

=

= P(-1.740)

= 0.0409.

Probability that -1.740 is calculated by using standard normal table(area under normal curve).in statistical table we have to see row -1.7 under column 0.04

Hence, P(z < -1.740) = 0.0409

Conclusion:

Therefore,If 25 women are randomly selected, the probability that the mean of their red blood cell counts is less than 4.444 is 0.0409.