In: Statistics and Probability
For each of the following two-samples t-tests (problems 1-6): (a) Determine if a F test for the ratio of two variances is appropriate to calculate for the context. If it is appropriate, conduct the analysis and report the result. Include what statistical conclusion you should draw from the analysis (i.e., whether you should conduct a pooled-variance t-test or an unequal-variances t-test). (b) Identify the most appropriate t-test to conduct for the situation/data given. Don’t forget to consider if the context requires one/two-tail tests. (c) Provide a statistical and practical interpretation of your findings.
3. How does cellphone service compare between different cities? The data stored in CellService represents the rating of Verizon and AT&T in 22 different cities (Data extracted from “Best Phones and Services,” Consumer Reports, January 2012, p. 28, 37). Is there evidence of a difference in the mean cellphone service rating between Verizon and AT&T? (Use a 0.05 level of significance)
City | Verizon | AT&T |
Atlanta | 56 | 74 |
Austin | 61 | 72 |
Boston | 60 | 69 |
Chicago | 55 | 73 |
Dallas-Fort Worth | 65 | 76 |
Denver | 56 | 72 |
Detroit | 63 | 73 |
Houston | 59 | 77 |
Kansas City | 66 | 74 |
Los Angeles | 56 | 73 |
Miami | 61 | 74 |
Milwaukee | 60 | 74 |
Minneapolis-St.Paul | 60 | 71 |
New York | 57 | 71 |
Philadelphia | 63 | 71 |
Phoenix | 62 | 76 |
San Diego | 60 | 74 |
San Francisco | 53 | 73 |
Seattle | 59 | 72 |
St. Louis | 64 | 73 |
Tampa | 67 | 73 |
Washington D. C. | 60 | 71 |