If the mean time between unscheduled maintenance of LCD displays in a hospital's CT scan facility is 4,000 operating hours, what is the probability of unscheduled maintenance in the next 5,000 hours?
A).8000
B).7135
C).2865
D).5000

Question

Quizplus · Accepted Answer

The probability of unscheduled maintenance in the next 5,000 hours is equal to the probability of unscheduled maintenance in any 5,000-hour period, which is 5,000 / 4,000 = 1.25. The probability of no unscheduled maintenance in the next 5,000 hours is equal to 1 - 1.25 = -0.25, which is not a valid probability. Therefore, the probability of unscheduled maintenance in the next 5,000 hours is 1.25, which is closest to choice B, 0.7135.

If the Mean Time Between Unscheduled Maintenance of LCD Displays