Twelve different video games showing substance use were obse

Twelve different video games showing substance use were observed and the duration times of game play (in seconds) are listed below. The design of the study justifies the assumption that the sample can be treated as a simple random sample. Use the data to construct a 95% confidence interval estimate of mu, the mean duration of game play. 4045 3876 3860 4031 4326 4808 4663 4028 5011 4833 4331 4315 Click here to view a t distribution table. Click here to view page 1 of the standard normal distribution table. Click here to view page 2 of the standard normal distribution table. What is the confidence interval estimate of the population mean mu? (Round to one decimal place as needed.)

Solution

sample size n=12

sample mean= 4343.917

sample standard deviation=398.0529

The degree of freedom =n-1=12-1=11

Given a=1-0.95=0.05, t(0.025, df=11) =2.20 (from student t table)

So the lower bound is

xbar -t*s/vn =4343.917 -2.2*398.0529/sqrt(12) =4091.1

So the upper bound is

xbar + t*s/vn=4343.917 +2.2*398.0529/sqrt(12) =4596.7