A random sample of high school students are asked the number of hours they spent on social media.

The hours are reported below: 3 5 6 7 8 10 12 13 14 15

You can assume the times are normally distributed with a standard deviation of 8.5.

a) Estimate with 90 percent confidence the mean number of hours spent on social media by all high school students.

Show all working as part of your answer.

b) Interpret your findings in part a)