1. The probability is .80 that a standard normal random variable is between -z and +z. The value of z is approximate?

a. 1.28

b. 1.35

c. 1.45

d. 1.96

2. A sample of 16 ATM transactions shows a mean transaction time of 67 seconds with a standard deviation of 12 seconds. State the hypotheses to test whether the mean transaction time exceeds 60 seconds

a. H₀: 60, H₁: >60

b. H₀: < 60, H₁: >=60

c. H₀: = 60, H₁: 60

d. H₀: 60, H₁: <60