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.