A child psychologist claims that video games increase the number of violent behaviors that children exhibit per week test the psychologist's claim, a school principal decided to conduct an experiment. The principal randomly selected 300 children and
assigned 150 of the children to at least 30 minutes of video game play per day. The principal then assigned the remaining
150 children to no video game play.
After observing the children for one year, the principal reported that, on average, children who played at least 30 minutes of video
games per day exhibited four more violent behaviors per week than children who did not play video games
What can be concluded from the principal's report?
OA. It can be concluded that children who do not play video games exhibit more violent behaviors per week than children
who play at least 30 minutes of video games per day.
OB. It can be concluded that children who play at least 30 minutes of video games per day exhibit more violent behaviors
per week than children who do not play video games
OC. There is not enough information to make any conclusions regarding the principal's report.
OD. It can be concluded that video games have no impact on the number of violent behaviors exhibited by children per
week
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A101 General podp

Jobs and productivity! how do retail stores rate? one way to answer this question is to examine annual profits per employee. the following data give annual profits per employee (in units of 1 thousand dollars per employee) for companies in retail sales. assume σ ≈ 4.0 thousand dollars. 3.7 6.7 3.6 8.5 7.5 5.9 8.7 6.4 2.6 2.9 8.1 −1.9 11.9 8.2 6.4 4.7 5.5 4.8 3.0 4.3 −6.0 1.5 2.9 4.8 −1.7 9.4 5.5 5.8 4.7 6.2 15.0 4.1 3.7 5.1 4.2 (a) use a calculator or appropriate computer software to find x for the preceding data. (round your answer to two decimal places.) thousand dollars per employee (b) let us say that the preceding data are representative of the entire sector of retail sales companies. find an 80% confidence interval for μ, the average annual profit per employee for retail sales. (round your answers to two decimal places.) lower limit -- thousand dollars upper limit -- thousand dollars (c) let us say that you are the manager of a retail store with a large number of employees. suppose the annual profits are less than 3 thousand dollars per employee. do you think this might be low compared with other retail stores? explain by referring to the confidence interval you computed in part (b). yes. this confidence interval suggests that the profits per employee are less than those of other retail stores. no. this confidence interval suggests that the profits per employee do not differ from those of other retail stores. correct: your answer is correct. (d) suppose the annual profits are more than 6.5 thousand dollars per employee. as store manager, would you feel somewhat better? explain by referring to the confidence interval you computed in part (b). yes. this confidence interval suggests that the profits per employee are greater than those of other retail stores. no. this confidence interval suggests that the profits per employee do not differ from those of other retail stores. (e) find an 95% confidence interval for μ, the average annual profit per employee for retail sales. (round your answers to two decimal places.) lower limit 3.75 incorrect: your answer is incorrect. thousand dollars upper limit 6.41 incorrect: your answer is incorrect. thousand dollars