a manufacturer of fluorescent light bulbs advertises that the distribution of the lifespans of these bulbs is normal with a mean of 9,000 hours and a standard deviation of 1,000 hours.
(a) What is the probability that a randomly chosen light bulb lasts more than 10,500 hours? (please round to four decimal places) (b) Describe the distribution of the mean lifespan of 15 light bulbs. O approximately normal with μ-9000 and σ 1000 . O approximately normal with μ = 9000 and σ =1000/ √15 O left skewed O right skewed (c) What is the probability that the mean lifespan of 15 randomly chosen light bulbs is more than 10,500 hours? (please round to four decimal places)
