- Let x be a random variable that represents the length of time it takes a student to complete Dr. Tracy Wang’s homework. From long experience, it is known that x has a normal distribution with mean
hours and standard deviation
hour.
Convert each of the following x intervals to standard z intervals.
(a)
(b)
(c)
(d)
Solution: (a) We have that
(b) We proceed analogously to get
(c) Similarly
(d)