Solve the following problems:
Q1: Confidence Interval for Effects of Marijuana Use on College Students:
Data:
Items sorted correctly by light marijuana users: n = 64, x = 53.3, s = 3.6
Items sorted correctly by heavy marijuana users: n = 65, x = 51.3, s = 4.5
Q: Refer to the sample data above and construct a 98% confidence interval for the difference between the two population means. Does the confidence interval include zero? What does the confidence interval suggest about the equality of the two population means?
Q2: Blanking Out on Tests
Monay students have had the unpleasant experience of panicking on a test because the first question was exceptionally difficult. The arrangement of test items was studied for its effect on anxiety. The following scores are measures of "debilitating test anxiety," which most of us call panic or blanking out (based on data from " Item Arrangement, Cognitive Entry Characteristics, Sex, and Test Anxiety as Predictors of Achievement in Examination Performance," by Klimko, Journal of Experimental Education, Vol. 52, No. 4.) Is there sufficient evidence to support the claim that the two populations of scores have the same mean? Is there sufficient evidence to support the claim that the arrangement of the test items has an effect on the score?
Questions Arrange from Easy to Difficult:
24.64 39.29 16.32 32.83 28.02
33.31 20.60 21.13 26.69 28.90
26.43 24.23 7.10 32.86 21.06
28.89 38.81 27.85 30.29 30.72
Questions Arrange from Difficult to Easy:
33.62 34.02 26.63 30.26
35.91 26.68 29.49 35.32
27.24 32.34 29.34 33.53