Q#4: IQ scores form a normal distribution with a mean of =105 and a standard deviation of = 15. Find the z-score corresponding to each of the following samples.

a. for X= 30 and a sample of n = 6 people?

b. for X= 90 and a sample of n = 35 people?

Q#5: IQ scores form a normal distribution with a mean of =105 and a standard deviation of = 15. What is the probability of obtaining a sample mean greater than M = 100?

a. for a sample of n = 36 people?

b. for a sample of n = 25 people?

Q#6: Find the probability by using Empirical Rule for the following (Do not use Z-table);

a. Given population mean of =100 and a standard deviation of = 15, find P(70

b. Given population mean of =100 and a standard deviation of = 15, find P(X>100).