82. The lifetime X (in hundreds of hours) of a certain type of vacuum tube has aWeibull distribution with parameters a2 and b3. Compute the following:

a. E(X) and V(X)

b. P(X 6)

c. P(1.5 X

6)

(This Weibull distribution is suggested as a model for time in service in “On the Assessment of Equipment Reliability: Trading Data Collection Costs for Precision,” J. Engrg. Manuf., 1991: 105–109).