Question

The amount of television viewed byâ today's youth is of primary concern to Parents Against Watching Televisionâ (PAWT). 300 parents of elementaryâ school-aged children were asked to estimate the number of hours per week that their child watches television. The mean and the standard deviation for their responses were 12 and 3â, respectively. PAWT constructed aâ stem-and-leaf display for the data that showed that the distribution of times was aâ symmetric, mound-shaped distribution. Give an interval where you believe approximatelyâ 95% of the television viewing times fell in the distribution.

a. less than 9 and more than 15 hours per week
b. between 3 and 21 hours per week
c. between 6 and 18 hours per week
d. less than 18

Answer 1

Option C. between 6 and 18 hours per week

Explanation:

We are given that distribution of times is symmetric and mound shaped and this implies that data is normally distributed.

We also know that in the normal distribution the 95% of data lies within 2 standard deviations i.e. mean± 2*standard deviation.

So, 95% of the television viewing times falls in interval

mean± 2*standard deviation

12±2*3

12±6

[6,18]

Thus, [6,18] is an interval where you believe approximately 95% of the television viewing times fell in the distribution.