Let X be a normal random variable with mean 5 and standard deviation 9. (X is N(5, 9))

a) Prob (9 < < 9.5) = ______________________

b) Find a such that Prob( < < 6) = 0.1 a = ____________________

c) Find a and b such that Prob( < < ) = 0.6, and such that a and b should be as close as possible. (The distance between them is as small as possible)

a = ____________________ , b = __________________

d) Prob( < < ) = 0.5, and Prob( < ) = 0.9. What are a and b ?

a = ____________________ , b = __________________