1. In its standardized form, the normal distribution
(a) has a mean of 0 and a standard deviation of 1.
(b) has a mean of 1 and a variance of 0.
(c) has an area equal to 0.5.
(d) cannot be used to approximate discrete probability distributions.
2. For some positive value of Z, the probability that a standard normal variable is between 0 and Z is 0.3770.
The value of Z is
(a) 0.18
(b) 0.81
(c) 1.16
(d) 1.47
3. For some value of z, the probability that a standard normal variable is below z is 0.2090. The value of Z is
(a) -0.81
(b) -0.31
(c) 0.31
(d) 1.96
4. For some positive value of X, the probability that a standard normal variable is between 0 and +2x is 0.1255.
The value of X is
(a) 0.99
(b) 0.40
(c) 0.32
(d) 0.16
5. If we know that the length of time it takes a college student to find a parking spot in the library parking lot follows a normal distribution with a mean of 35. minutes and a standard deviation of minute, find the probability that a randomly selected college student will find a parking spot in the library parking lot in less than 3 minutes.
(a) 0.3551
(b) 0.3085
(c) 0.2674
(d) 0.1915
