The probability density function for the continuous random variable X is given by: (A(x² – 2x + 21) 0

The probability density function for the continuous random variable X is given by: (А(х? — 2х + 21) 0

The probability that none of the three bulbs in a set of traffic lights will have to be replaced during the first 1200 hours of operation if the lifetime X of a bulb (in thousands of hours) is a random variable with probability density function f(x) = 6[0.25-(x-1.5)2] when 1 ≤ x ≤ 2 and f(x) = 0 otherwise is