The First Exam – Part II Math 311, Winter 2002 January 30, 2003 Name: ______________________________ _____________________________________________________________________________________________________________ All pertinent work must be shown neatly and correctly. Points will be deducted for incorrect, missing, or unclear work regardless of the final answer. Complete English sentences must be given for all “short answer” type questions. Draw a circle or a box around your answer. 1. John's parents recorded his height at various ages up to 66 months. Below is a record of the results. Age (months) Height (inches) 36 35 48 38 54 41 60 43 66 45 a. (8 points) Find a least-squares regression line that can be used to predict John’s height using his age. b. (2 points) Use the equation found above to predict John’s height when he is 62 months. c. (5 points) Describe, using the appropriate quantifiers, the strength of the relationship Age and Height share. 2. (10 points) Many test preparation companies claim to be able to increase their client’s SAT scores. Below are the SAT scores of 40 students selected at random from a group of students who took the SAT exam twice. The first time they took the exam was before enrolling in the test prep program and the second time was after completing the program. The scores are arranged randomly. They can also be found in the Minitab worksheet. Before After 680 670 660 680 580 700 730 700 650 630 700 780 650 620 730 770 640 660 730 710 620 650 740 670 650 780 700 730 710 700 610 700 680 620 700 690 760 700 630 630 Use these data to assess the claims of the test prep company. Do you agree or disagree with the company’s claim? Support your opinion statistically. 3. (10 points) Based upon 1997 figures, the following are 110 “waiting times” (in minutes) between eruptions of the Old Faithful Geyser in Yellowstone National Park. These times are also recorded in the Minitab worksheet. 81 94 91 76 91 53 82 74 83 89 80 69 83 83 89 98 94 35 83 78 67 62 76 94 73 80 91 42 85 107 55 82 78 74 89 76 60 60 98 82 94 91 82 82 65 85 74 73 89 118 82 69 69 89 89 83 105 60 82 92 98 112 80 64 73 65 40 69 80 82 56 69 82 71 87 85 83 85 94 80 60 80 98 51 78 73 83 69 71 91 67 73 33 82 78 73 73 73 74 87 65 74 74 108 87 83 73 67 64 80 Describe these data. Include any and all numerical or graphical summaries you feel are appropriate. DO NOT simply list a series of numbers. Explain your findings.