Suppose that the lifetimes of light bulbs are approximately normally distributed, with a mean of

56

hours and a standard deviation of

3.2

hours. With this information, answer the following questions.(a) What proportion of light bulbs will last more than

61

hours?(b) What proportion of light bulbs will last

53

hours or less?(c) What proportion of light bulbs will last between

59

and

62

hours?(d) What is the probability that a randomly selected light bulb lasts less than

46

hours?