A study indicates that? 18- to? 24- year olds spend a mean of 120 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 20 minutes.
a. What is the probability that an? 18- to? 24-year-old spends less than 95 minutes watching video on his or her smartphone per? month?
?(Round to four decimal places as? needed.)
b. What is the probability that an? 18- to? 24-year-old spends between 95 and 150 minutes watching video on his or her smartphone per? month?
?(Round to four decimal places as? needed.)
c. What is the probability that an? 18- to? 24-year-old spends more than 150 minutes watching video on his or her smartphone per? month?
?(Round to four decimal places as? needed.)
d. Five percent of all? 18- to? 24-year-olds will spend less than how many minutes watching video on his or her smartphone per? month?
?(Round to two decimal places as? needed.)