Question

7 Find the 90% confidence interval for the population standard deviation given the following (1 point n 55, -11.49,s 2.34 and the distribution is normal. 0192 <σ<3.25 o 2.09 2.92 1.37<σ< 1.01 10.28 σ< 14.32 8. Twelve different video games showing product placement were observed and the duration ( point) 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 050 sec < ơ < 16.0 sec 38.0 sec < ơ< 115.2 sec 42.6 sec < σ< 121.7 sec 39.0 sec < 125.2 sec

Answer 1

7)

from above nearest correct option 90% CI : 2.09 < $\sigma$ < 2.92

8)

from above 99% CI =39.0 sec < $\sigma$ < 125.2