4. Suppose that a random variable X is normally distributed with = 4 and 2 = 4. If the lifetime Y (hours), of an

4. Suppose that a random variable X is normally distributed with μ = 4 and σ2 =

4. If the lifetime Y (hours), of an electronic component can be modeled with the 206 5 Continuous Random Variables distribution of the random variable Y = eX, then find the following:

(a) the mean and the standard deviation of Y,

(b) P(Y >4000),

(c) P(Y ≤ 5000).