2. For a brand of light bulb the probability density
function of the life span of the light bulb is given by the function below,
where t is in months.
(a)
Verify that is a probability density function.
(b)
What is the probability that a light bulb will have a
life span less than 8 months?
(c)
What is the probability that a light bulb will have a
life span more than 20 months?
(d)
What is the probability that a light bulb will have a
life span between 14 and 30 months?
(e)
Determine the mean value of the life span of the light
bulbs.
[Solution]