Suppose that you're thinking about buying a used R-car at Honest Abe's. In order to make an informed decision you look up the records in an auto magazine and find that 30% of these cars have a faulty transmission. To get more information you hire a mechanic who is excellent: Of all the faulty cars he has examined in the past he correctly judged that 90% were "faulty" and only erroneously judged 10% as "OK." He 's almost as good at judging good cars: Of all the good cars he's correctly judged that 80% were "good" and only erroneously judged 20% as "faulty." What is the probability that the R-car you're thinking of buying has a faulty transmission before you hire the mechanic? .27 .24 .30 .20 .41

Imagine that you were hired as a consultant by a local business owner tohelp her determine how many paid days off she should provide to her employees. In general, she wants to establish some sort of standard for her employees and for herself. Based on data provided by the government, you conclude that on average, workers in the United States take 14 paid days off per year. The data for the eight employees who work at the company you are consulting for are: 12, 9, 7, 12, 13, 14, 14, and 12 days. Thequestion you are trying to answer is, are the number of days off taken by the eight employees statistically different from the data provided by the US government? (I have stated the null and alternative hypotheses, and found that this is a two-tailed test. With alpha=0.05, I have found the t-critical value to be +/- 2.365, with DF=7)I need help with:  A. Compute the appropriate test statistic. Use the computational formula tocompute the sample standard deviation. Show all formulas that you…

. A school psychologist wants to test the effectiveness of a new method for teaching reading. She takes 500 first grade students from District 12 (all with the same teacher), and randomly assigns half of them to the traditional method and half of them to the new method for teaching reading. The students are not told which teaching method they are being taught with. At the end of the year, she obtains all scores on a reading achievement test, and looks for any differences between the two groups. a. What is the research objective? b. What type of study was used? Give the exact name. c. Does this study make use of random sampling, random assignment, both, or neither? How do you know? d. What are the explanatory and response variables? Explanatory Variable: Response Variable: e. What are the treatments? e. Was blinding used? If so, how?

Suppose in our school, 60% are male students, and 40% are female students. The percertage for getting grade A for all students is 25%, and for male students is 20%. What is the percertage for getting grade A for female students ? 13.0 20.0 32.5 34.5