Question

A random sample of 49 teenagers from a large population was surveyed, and the average number of movies that they had rented in the past week was x = 1.9, with a sample standard deviation of s = 0.5. a) Construct a 95% confidence interval for the average number of movies rented by teenagers in a week. b) Construct a 99% confidence interval for the average number of movies rented by teenagers in a week.t v

Answer 1

It is given that the sample size, n=49(>30), sample mean=x̅ = 1.9 and sample standard deviation= s=0.5

Here, since the sample size is large enough (>30), we can estimate population standard deviation σ= s=0.5 and to find a confidence interval, we will use Z-test which is as below: