Question 5 The lifetimes, in hours, of a certain make of light bulbs are assumed to be Normally distributed with a mean
Posted: Thu May 05, 2022 8:22 pm
Question 5 The lifetimes, in hours, of a certain make of light bulbs are assumed to be Normally distributed with a mean of 5500 hours and a standard deviation of 120. a) Find the probability that the lifetime of a light bulb picked at random will exceed 5764 hours. [3] b) Determine the lifetime not achieved by 0.4% of these light bulbs. [3] Thirty of these light bulbs are selected. c) Find the probability that two out of these thirty light bulbs will have a lifetime exceeding 5764 hours. [4]