Homework answers / question archive / Name ______________________ Business Statistics Free Response Questions #8: for Chapter 12 Worth 10 points

Name ______________________ Business Statistics Free Response Questions #8: for Chapter 12 Worth 10 points

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Name ______________________ Business Statistics Free Response Questions #8: for Chapter 12 Worth 10 points. Directions: You can either type out answers to these questions then submit a word document or pdf (please no GoogleDoc sharing links or Apple pages files) or you can write out your answer by hand and take a photo (try to avoid HEIC image format, please) or scan the sheet of paper. PLEASE make sure you hand in something that is aligned correctly (not sideways) and clear enough for me to read. 1. A city wants to know if a new advertising campaign to make citizens aware of the dangers of driving after drinking has been effective. The goal would be to lower the number of DUIs after the new campaign. They count the number of drivers who have been stopped with more alcohol in their systems than the law allows for each day of the week in the week before and the week a month after the campaign starts. Give the StatCrunch output(s) to support your answer. **Make sure you provide images or screenshots of your StatCrunch output, you will lose points if you don’t. a) Are the data paired? Explain. b) Compute the mean difference. You can do this by hand or use StatCrunch. c) Compute the standard deviation of the differences. d) Compute the standard error of the mean difference. e) Find the value of the t-statistic. f) How many degrees of freedom does the t-statistic have? g) Is the alternative one- or two-sided? Explain. h) What is the P-value associated with this t-statistic? (Assume that the other assumptions and conditions for inference are met.) i) At α = 0.05, what do you conclude? Day of Week After Before M 3 5 T 1 5 W 2 2 Th 2 5 F 4 8 S 6 13 Su 4 8 2. People’s magazine conducts surveys to gauge how the Internet and technology impact daily life of people. One might suspect that younger and older respondents might differ in their opinions of whether computers and technology give them more control over their lives. A subset of the data from this survey shows the mean ages of two groups of respondents, those who reported that they believed that computers and technology give them “more” control and those that reported “less” control. Give the StatCrunch output to support your answer. **Make sure you provide images or screenshots of your StatCrunch output, you will lose points if you don’t. a) Find the 90% confidence interval for the difference in mean age between the two groups of respondents. b) With this confidence interval, can you say the two groups are different? Explain. Group n mean stdev More 72 49.3 20.1 Less 28 49.0 18.2