Groundhog Day Eve

  1. The dataset spanish-test.data gives pre-test and post-test scores on the MLA listening test in Spanish for 20 high school spanish teachers who attended an intensive summer course in Spanish. Does attending the institute improve listening skills?
    1. Check the data graphically and numerically for outliers, non-normality, or anything else untoward. Report what you see.
    2. Give 90 and 95 percent confidence interval for the mean increase in test score.
    3. State appropriate null and alternative hypotheses for a hypothesis test.
    4. Carry out your hypothesis test and relate the conclusion to your confidence intervals above.
    5. Compute 99 and 98 percent confidence intervals for the mean increase in test score. What changes between the two?
    6. Adjust the confidence level to see exactly where the change occurs.
  2. The data set study-habits.data gives results for students at a selective private college on the Survey of Study Habits and Attitudes (SSHA), a psychological test designed to measure the motivation, attitudes, and study habits of college students. Most studies have found that the mean SSHA score is lower for men than that for women.
    1. Again check the data graphically and numerically for outliers, non-normality, or anything else untoward. Report what you see.
    2. Do these data support the claim that the mean SSHA score is lower for men than for women? (Use both a confidence interval and a hypothesis test to answer this question.)