Question

# A study indicates that​ 18- to​ 24- year olds spend a mean of 145 minutes watching...

A study indicates that​ 18- to​ 24- year olds spend a mean of 145 minutes watching video on their smartphones per month. Assume that the amount of time watching video on a smartphone per month is normally distributed and that the standard deviation is 10 minutes. Complete parts​ (a) through​ (d) below.

a.What is the probability that an​ 18- to​ 24-year-old spends less than 140 minutes watching video on his or her smartphone per​ month?The probability that an​ 18- to​ 24-year-old spends less than 140 minutes watching video on his or her smartphone per month is nothing.

​(Round to four decimal places as​ needed.)

b. What is the probability that an​ 18- to​ 24-year-old spends between 140 and 165 minutes watching video on his or her smartphone per​ month?The probability that an​ 18- to​ 24-year-old spends between 140 and 165 minutes watching video on his or her smartphone per month is nothing.

​(Round to four decimal places as​ needed.)

c. What is the probability that an​ 18- to​ 24-year-old spends more than 165 minutes watching video on his or her smartphone per​ month?The probability that an​ 18- to​ 24-year-old spends more than 165 minutes watching video on his or her smartphone per month is nothing.

​(Round to four decimal places as​ needed.)

d.One percent of all​ 18- to​ 24-year-olds will spend less than how many minutes watching video on his or her smartphone per​ month? One percent of all​ 18- to​ 24-year-olds will spend less than nothing minutes watching video on his or her smartphone per month.

Thank you.