Twelve different video games showing product placement were observed and the duration times of game play (in seconds) were recorded and found to have a normal distribution. The design of the study justifies the assumption that the sample can be treated as a simple random sample. Given a sample standard deviation of 60.9 sec, use the sample data to construct a 99% confidence interval estimate of σ, the standard deviation of the duration times of game play. 42.6 sec < σ < 121.7 sec

5.0 sec < σ < 16.0 sec

39.0 sec < σ < 125.2 sec

38.0 sec < σ < 115.2 sec