Question

In: Statistics and Probability

A study indicates that​ 18- to​ 24- year olds spend a mean of 115 minutes watching...

A study indicates that​ 18- to​ 24- year olds spend a mean of 115 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 15 minutes. Complete parts​ (a) through​ (d) below.

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 135 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
135 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?

Solutions

Expert Solution

Let X denote the time spent (in minute ) by on 18 to 24 year old on watching videos


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