1.) Xhas a normal distribution with the given mean and a standard deviation. Find the indicated probability. (Round your answer to four decimal places.)

=92,= 15, findP(113X131)

2.) Find the probability that a normal variable takes on values within0.6standard deviations of its mean. (Round your decimal to four decimal places.)

3.) SupposeXis a normal random variable with mean=90and standard deviation=10. Findbsuch thatP(90Xb) = 0.3.

HINT [See Example 3.] (Round your answer to one decimal place.)

4.) SupposeXis a normal random variable with mean= 100 and standard deviation= 10. Findasuch thatP(Xa) =0.04.

(Round your answer to one decimal place.)