Question

A Gallup poll conducted January 17 - February 6, 2019, asked 1024 teenagers 13 years of age to 17 years of age , “Typically, how many hours per week do you spend watching TV?’’ The teenagers who participated in the survey watched, on average, 13.0 hours of television per week with a standard deviation of 2.3 hours per week. Construct a 95% confidence interval for the average number of hours that teenagers watch TV each week

Answer 1

Number of teenagers asked = n = 1024.

Mean = x̄ = 13.0 hours per week

Standard deviation = s = 2.3 hours per week

As sample size is quite large, we will use z-score to find the confidence interval.

z-table :

z score = z = 1.96

Confidence Interval for population mean(µ) is given as -

Therefore, a 95% confidence interval for the average number of hours that teenagers watch TV each week is (12.8591 hours per week, 13.1409 hours per week).