1) Suppose that local train speeds at an interstate location have a normal distribution with a mean equal to 70 mph and standard deviation equal to 8 mph. What is the z-score for a speed of 64 mph

a) 0.75

b) -0.75

c) 0.65

d) -0.65

2) In a standard normal distribution the probability given in the table corresponding the z value 2.2 is

a) 0.9861

b) 0.9368

c) 0.8368

d) answer not given

3) "Find the expectation of a random variable X? if X = 9, 11, 12, 13, 14, and P(X) = 0.2, 0.25, 0.3, 0.15, 0.1 respectivley "

a) 11.5

b) 4.5

c) 9.5

d) 14.5

4) "Find the Mean of f(x), where f(x) = 5X+5. The probability distribution of a random variable X ; if X = 12, 14, 15, 16, 17, and P(X) = 0.2, 0.25, 0.3, 0.15, 0.1 respectively"

a) 11

b) 37.5

c) 42

d) 77.5