# Standard distribution, deviation, etc.

15. If P(A) = 0.4, P(B| A) = 0.35, P(A  B) =0.69, then P(B) =

a. 0.14

b. 0.43

c. 0.75

d. 0.59

18. If X and Y are mutually exclusive events with P(X) = 0.295, P(Y) = 0.32, then P(XY) =

a. 0.0944

b. 0.6150

c. 1.0000

d. 0.0000

27. For a standard normal distribution, the probability of z  0 is

a. zero

b. -0.5

c. 0.5

d. one

28. Z is a standard normal random variable. The P(-1.96  Z  -1.4) equals

a. 0.8942

b. 0.0558

c. 0.475

d. 0.4192

29. The weight of football players is normally distributed with a mean of 200 pounds and a standard deviation of 25 pounds. The probability of a player weighing less than 250 pounds is

a. 0.4772

b. 0.9772

c. 0.0528

d. 0.5000

31. A population has a standard deviation of 16. If a sample of size 64 is selected from this population, what is the probability that the sample mean will be within 2 of the population mean?

a. 0.6826

b. 0.3413

c. -0.6826

d. Since the mean is not given, there is no answer to this question.

https://brainmass.com/statistics/normal-distribution/standard-distribution-deviation-etc-41763

#### Solution Summary

The solution is provided in an attachment and includes explanations to the multiple choice answers and references.