Please zoom! Two different professors teach an introductory statistics course. T
ID: 3243965 • Letter: P
Question
Please zoom!
Two different professors teach an introductory statistics course. The table shows the distribution of final grades they reported We wonder whether one of these professors is an "easier" grader: Complete parts a through f. a) Will you test goodness-of fit, homogeneity, or independence? A. Independence B. Homogeneity C. Goodness-of-fit b) Write the appropriate hypotheses. Choose the correct answer below A. H_0: The distribution of grades is the same for the two professors H_A: The grades are higher for the first professor. B. H_0: The distribution of grades is different for the two professors. H_A: The distribution of grades is the same for the two professors C. H_0: The distribution of grades is the same for the two professors. H_A: The distribution of grades is different for the two professors. D. H_0: The distribution of grades is the same for the two professors. H_A: The grades are higher for the second professor. c) Find the expected counts for each cell and explain why the chi-square procedures are not appropriate for this table. Explain why the chi-square procedures are not appropriate for this table Choose the correct answer below. A. Since the classes were not sampled at random, the chi-square procedures are not appropriate B. Since some of the cells have expected counts less than 5, the chi-square procedures are not appropriate C. Since the data are not counts for the categories, the chi-square procedures are not appropriate d) Create a new table by containing categories so that a chi-square procedure can be used. Combine the grades to be "acceptable" Let an acceptable grade be "A" "B" and "C" and an unacceptable grade be "D" and "F". Find the expected counts for each cell to confirm whether the chi-square procedure can be used. e) With this change in the table, what has happened to the number of degrees of freedom? Select the correct choice below and, if necessary, fill in the answer boxes to complete your choice. A. decreased from to B. stayed the same C. increased from to f) Test the hypothesis about the two groups and state an appropriate conclusion. Let alpha = 0.05. Use the hypotheses found in part band the observed and expected counts from part d. Now find the chi^2 test statistic. d) Find the P-value of the test statistic. P-value = State the conclusion to the hypothesis test Choose the correct answer below. A. Fail to reject the null hypothesis: There is not a difference in the distribution of final grades for the two professors. B. Fail to reject the null hypothesis: There is a difference in the distribution of final grades for the two professors. C. Reject the null hypothesis. There is a difference in the distribution of final grades for the two professors. D. Reject the null hypothesis. There is not difference in the distribution of final grades for the two professors.Explanation / Answer
homogeneity
h0;there is no diference in the grade distribution reported by the two professors
Ha:there is diference in the grade distribution reported by the two professors
row total*column total/total
4 10 -----> 7.7368 6.2631
11 11 12.15 9.8442
13 9 11.6052 9.3947
9 2 6.0789 4.9210
5 2 3.8684 3.1315