The file examanxietytxt on Canvas contains information on a

The file examanxiety.txt on Canvas contains information on a number of variables:

Code   Revise   Exam   Anxiety   Gender
1   4   40   86.298   Male
2   11   65   88.716   Female
3   27   80   70.178   Male
4   53   80   61.312   Male
5   4   40   89.522   Male
6   22   70   60.506   Female
7   16   20   81.462   Female
8   21   55   75.82   Female
9   25   50   69.372   Female
10   18   40   82.268   Female
11   18   45   79.044   Male
12   16   85   80.656   Male
13   13   70   70.178   Male
14   18   50   75.014   Female
15   98   95   34.714   Male
16   1   70   95.164   Male
17   14   95   75.82   Male
18   29   95   79.044   Female
19   4   50   91.134   Female
20   23   60   64.536   Male
21   14   80   80.656   Male
22   12   75   77.432   Male
23   22   85   65.342   Female
24   84   90   56.116   Female
25   23   30   71.79   Female
26   26   60   81.462   Female
27   24   75   63.73   Male
28   72   75   27.46   Female
29   37   27   73.402   Female
30   10   20   89.522   Male
31   3   75   89.522   Female
32   36   90   75.014   Female
33   43   60   43.58   Male
34   19   30   82.268   Male
35   12   80   79.044   Male
36   9   10   79.044   Female
37   72   85   37.132   Male
38   10   7   81.462   Male
39   12   5   83.074   Female
40   30   85   50.834   Male
41   15   20   82.268   Male
42   8   45   78.238   Female
43   34   60   72.596   Male
44   22   70   74.208   Female
45   21   50   75.82   Female
46   27   25   70.984   Male
47   6   50   97.582   Male
48   18   40   67.76   Male
49   8   80   75.014   Male
50   19   50   73.402   Female
51   0   35   93.552   Female
52   52   80   58.894   Female
53   38   50   53.252   Female
54   19   49   84.686   Male
55   23   75   89.522   Female
56   11   25   71.79   Female
57   27   65   82.268   Male
58   17   80   69.372   Male
59   13   50   62.118   Male
60   42   70   68.566   Female
61   4   40   93.552   Male
62   8   80   84.686   Female
63   6   10   82.268   Male
64   11   20   81.462   Female
65   7   40   82.268   Male
66   15   40   91.134   Male
67   4   70   91.94   Female
68   28   52   86.298   Female
69   22   50   72.596   Male
70   29   60   63.73   Female
71   2   80   63.73   Male
72   16   60   71.79   Female
73   59   65   57.282   Male
74   10   15   84.686   Female
75   13   85   84.686   Male
76   8   20   77.432   Female
77   5   80   82.268   Female
78   2   100   10   Male
79   38   100   50.834   Female
80   4   80   87.91   Male
81   10   10   83.88   Male
82   6   70   84.686   Female
83   68   100   20.206   Female
84   8   70   87.104   Male
85   1   70   83.88   Female
86   14   65   67.76   Male
87   42   75   95.97   Female
88   13   85   62.118   Female
89   1   30   84.686   Male
90   3   5   92.746   Male
91   5   10   84.686   Female
92   12   90   83.074   Female
93   19   70   73.402   Male
94   2   20   87.91   Female
95   19   85   71.79   Male
96   11   35   86.298   Male
97   15   30   84.686   Female
98   23   70   75.82   Male
99   13   55   70.984   Female
100   14   75   78.238   Female
101   1   2   82.268   Male
102   9   40   79.044   Male
103   20   50   91.134   Female

• Exam: score on a math exam
• Revise: hours spend revising for the math exam
• Anxiety: “math anxiety” on a scale from 0 to 100 (100 is most anxious)

(a) Find the regression line to predict exam score from anxiety. Write down your answer as
an equation.
(b) Which of the following regression assumptions are met?
i. Linearity
ii. Independence
iii. Equal variance (homoskedasticity)
iv. Normality of errors
(c) Suppose we want to make probabilistic predictions of a student’s exam score given their
math anxiety. Should we use the bivariate normal? Why or why not?

Solution