Project 81
For this project, you may assume that the exam scores in this data set are in some sense a simple random sample from all possible exams scores students would earn when taking the quizzes or finals in question. Find a 95% confidence interval for the mean of the differences between the Spring 2007 quiz scores and the Spring 2007 final exam scores. (Again, “mean” refers here to the theoretical means over all possible introductory statistics students who might take these quizzes as part of the course.)
In Chuck Hommel's Introduction to Applied Statistics course at the University of Puget Sound, he gives periodic homework quizzes. These are given on Mondays, take about ten minutes, and cover the homework that students have had a chance both to try and to ask about in class. The quizzes include a selection of two or three homework problems taken directly from the text. Students can copy their homework onto the quiz paper. In theory, if the student has done the homework, the quiz should be easy. Over a semester, there will be four or five quizzes.
At the end of the semester, all students take a comprehensive final examination. This exam is taken during a two-hour period and contains original questions the students have not previously seen.
Homework quiz scores are between 0 and 5 points. For each student, the mean quiz score is calculated and a percent correct is calculated by dividing the mean by 5 and multiplying by 100. This results in an overall homework quiz score in the range 0 to 100. The final exam is scored on a scale of 0 to 100. A five-point extra credit question means the highest possible final exam score is 105.
Data was collected from four sections of Introduction to Applied Statistics taught during the Fall semester of 2006 and the Spring and Fall semesters of 2007. A total of 97 students were enrolled.
Homework quiz averages and final exam scores were collected for all 97 students who completed Chuck Hommel's Introduction to Applied Statistics classes at the University of Puget Sound for the Fall 2006, Spring 2007, and Fall 2007 semesters.
The variables in the data set are as follows:
Name | Units | Description |
term | F06 = Fall 2006 semester, S07 = Spring 2007 semester, F07 = Fall 2007 semester | course semester |
quizAvg | percent (0-100) | average of homework quiz scores |
finalExam | points (0-105) | score on final exam |
The full data set in csv format is at: