Suppose x has a distribution with a mean of 70 and a standard deviation of 3. Random samples of size
n = 36
are drawn.

(a) Describe the
x distribution
and compute the mean and standard deviation of the distribution.
x
has
an approximately normal


distribution with
mean x =
70


standard deviation x =
3



(b) Find the z value corresponding to
x = 69.5.

z =


(c) Find
P(x < 69.5).
(Round your answer to four decimal places.)
P(x < 69.5) =