Answer Happy

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 o, the standard deviation of the duration times of game play. Assume that this sample was obtained from a population with a normal distribution. 3,842 4,653 4,505 3,994 3,930 4,883 5,047 4,478 The confidence interval estimate is sec<< (Round to one decimal place as needed.) sec. 4,934 3,819 4,799 4,361
Assume that the sample is a simple random sample obtained from a normally distributed population of IQ scores of statistics professors. Use the table below to find the minimum sample size needed to be 95% confident that the sample standard deviations is within 30% of a. Is this sample size practical? 6 To be 95% confident that s is within of the value of 6, the sample size In should be at least To be 99% confident that s is within of the value of 6, the sample size In should be at least 1% 5% 10% 20% 30% 40% 50% 19,205 768 192 48 21 12 8 5% 10% 20% 30% 40% 50% 33,218 1,336 336 85 38 22
The minimum sample size needed is 21 Is this sample size practical? ERELEMEN OA. Yes, because the sample size is small enough to be practical for most applications. OB. No, because the sample size should be as small as possible for most applications. OC. No, because the sample size is excessively large to be practical for most applications. D. Yes, because the sample size should be as large as possible for most applications.