6 If z is a standard normal random variable the area between z 0 and z 1 2 compared to the area between z 1 2 and z 2 4 will be b smaller c the same a larger d Not Enough Info 7 The probability density function f x of a random variable X that is normally distributed is completely determined once the a mean and standard deviation of X are specified b mean and mode of X are specified c median and mode of X are specified d mean and median of X are specified 8 The exponential distribution is often concerned with a the number of failures in an experiment b the amount of time until an event occurs c the number of successes in an experiment d events that are equally likely to happen