7.94 Let x denote the IQ of an individual selected at random from a certain population. The value of x must be a whole number. Suppose that the distribution of x can be approximated by a normal distribution with mean value 100 and standard deviation 15. Approximate the following probabilities. (Hint: See Example 7.34.)

a. P(x 5 100)

b. P(x # 110)

c. P(x , 110) (Hint: x , 110 is the same as x # 109.)

d. P(75 # x # 125)