1) Find the value of z such that the area between -z and +z is 97.6% of the total area under the standard normal curve.

A. 2.25

B. 1.96

C. 2.58

D. 2.36

E. 2.26

2) The scores on a certain test are normally distributed with mean 61 and standard deviation 3. What is the probability that a sample of 100 students will have a mean score more than 61.3?

A. 0.4602

B. 0.3413

C. 0.8413

D. 0.1587

E. none of the above

3) A random sample of 66 observations was taken from a large population. The population proportion is 12%. The probability that the sample proportion will be more than 17% is

A. 0.0568

B. 0.8944

C. 0.1056

D. 0.4222

E. None of the above

4) .Assume a Normal Distribution with mean = 98.7 and IQR = 0.67. Find the standard deviation.

A. 0.37

B. 0.45

C. 0.50

D. 1.50

E. none of the above