Question

# Twelve different video games showing substance use were observed and the duration of times of game...

Twelve different video games showing substance use were observed and the duration of 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 sample data to construct an 80​% confidence interval estimate of σ​, the standard deviation of the duration times of game play. Assume that this sample was obtained from a population with a normal distribution.

4,608 4,760 3,816 3,867 4,572 3,913

4,751 5,009 4,312 3,858 4,493 4,413

Suppose, random variable X denotes duration (in seconds) of times of game play.

Corresponding statistic is given by

Here,

Sample size

Sample variance

Degrees of freedom

We know,

[Using R-code 'qchisq((1-0.80)/2,11)' and 'qchisq(1-(1-0.80)/2,11)']

Hence, 80% confidence interval estimate of , standard deviation of duration is (327.593, 576.518).

#### Earn Coins

Coins can be redeemed for fabulous gifts.