Answer Happy

Suppose that the lifetimes of light bulbs are approximately
normally​ distributed, with a mean of 56 hours and a
standard deviation of 3.3 hours. With
this​ information, answer the following questions.​
(a) What proportion of light bulbs will last more
than 60 ​hours?
​(b) What proportion of light bulbs will last 50 hours
or​ less?​
(c) What proportion of light bulbs will last
between 58 and 62 ​hours?​(d) What is the
probability that a randomly selected light bulb lasts less
than 46 ​hours?
Question content area bottom
Part 1
​(a) The proportion of light bulbs that last more
than 60 hours is
enter your response here.
​(Round to four decimal places as​ needed.)
Part 2
​(b) The proportion of light bulbs that last 50 hours
or less is
enter your response here.
​(Round to four decimal places as​ needed.)
Part 3
​(c) The proportion of light bulbs that lasts
between 58 and 62 hours is
enter your response here.
​(Round to four decimal places as​ needed.)
Part 4
​(d) The probability that a randomly selected light bulbs lasts
less than 46 hours is
enter your response here.
​(Round to four decimal places as​ needed.)