Problem 3 (1 point)

The lifetime of a certain brand of lightbulb has an exponential distribution with

a mean of 800 hours. Use R to answer the following questions. [Hint: Using

help() to learn R functions (e.g., dexp,pexp,qexp,rexp) related to the exponential

distribution.]

(a) Find the probability that a randomly selected lightbulb of this kind lasts 700 to

900 hours.

(b) Find the probability that a randomly selected lightbulb of this kind lasts longer

than 850 hours.

(c) Find the 80th percentile of the lifetime of this kind of lightbulb.

Note: To get full points, include R codes in the appendix sections