1.) = 60 months

= 2 months

a.) P(X > 68) = P(z > (x - ) / )

= P(z > (68 - 60) / 2)

= P(z > 4)

= 1 - P(z > 4)

= 1 - 1 = 0.0000

b.) P(z < (x - ) / )

= P(z < (63 - 60) / 2)

= P(z < 1.5)

= 0.9332

c.) P(58 < X < 65) = P((x - ) / ) < z < ((y- ) / )

= P((58 - 60) / 2 < z < (65 - 60) / 2)

= P(-1 < z < 2.5)

= P(z < 2.5) - P(z < -1)

= 0.9938 - 0.1587 = 0.8351

Using the information in the problem above, what is the probability that a sample average () from a sample of 25 components will be between 58.5 and 59.6 months?