Question: A light fixture holds two lightbulbs. Bulb A is of a type whose lifetime is normally distributed with mean 800 hours and standard deviation 100

A light fixture holds two lightbulbs. Bulb A is of a type whose lifetime is normally distributed with mean 800 hours and standard deviation 100 hours. Bulb B has a lifetime that is normally distributed with mean 900 hours and standard deviation 150 hours. Assume that the lifetimes of the bulbs are independent.
a. What is the probability that bulb B lasts longer than bulb A?
b. What is the probability that bulb B lasts more than 200 hours longer than bulb A?
c. Another light fixture holds only one bulb. A bulb of type A is installed, and when it burns out, a bulb of type B is installed. What is the probability that the total lifetime of the two bulbs is more than 2000 hours?

Step by Step Solution

3.43 Rating (166 Votes )

There are 3 Steps involved in it

1 Expert Approved Answer
Step: 1 Unlock

Let X be the lifetime of bulb A and let Y be the lifetime of bulb B Then X N800 1002 and Y N900 1502 ... View full answer

blur-text-image
Question Has Been Solved by an Expert!

Get step-by-step solutions from verified subject matter experts

Step: 2 Unlock
Step: 3 Unlock

Document Format (1 attachment)

Word file Icon

944-S-J-P-D (2166).docx

120 KBs Word File

Students Have Also Explored These Related Statistics Questions!