9.5 Data are gathered on 16 students. Half of the students are randomly assigned to a new tutoring program, and half have their usual school experience. A study finds that test scores for the tutoring program students are on average 10 points higher than those for the other students. The p value for a test of improvement from the program is 0.3, not significant at even the 10% level. a. If mean test scores are 200 and the standard deviation is 40, are these results practically significant, in your opinion? Explain what practical significance means. b. Explain what causes this result to be not statistically significant. c. Do you conclude that the tutoring program is ineffective because the results are not statistically significant?9.6 A recent poll found that 60 percent of Americans support raising taxes on incomes above $250,000. The details for the poll results stated that the "margin of sampling error is plus or minus 3.5 percentage points." a. Calculate the 95% confidence interval for support for that policy. b. Interpret the 95% confidence interval in words. c. A prior poll had shown 55 percent of Americans supporting the policy. Are the results of the recent poll (60%) statistically significantly different from the prior poll results (55%)? d. Express the change in the results between the prior poll and the current poll in two different ways. e. The poll also broke down the policy support results by region of the country. Explain how the margin of error would differ for the results for just the Midwest and why