Question

The SAT and the ACT are the two major standardized tests that colleges use to evaluate candidates. Most students take just one of these tests. However, some students take both. The data data91.dat gives the scores of 60 students who did this. How can we relate the two tests?

(b) Find the least-squares regression line and draw it on your plot. Give the results of the significance test for the slope. (Round your regression slope and intercept to three decimal places, your test statistic to two decimal places, and your P-value to four decimal places.)

ACT =	___+ __  (SAT)
t =
P =

(c) What is the correlation between the two tests? (Round your answer to three decimal places.)

obs     sat     act
1       1203    28
2       827     17
3       622     15
4       712     16
5       1069    30
6       984     22
7       1172    26
8       963     20
9       848     15
10      1028    16
11      778     17
12      623     12
13      1110    22
14      740     15
15      1023    19
16      1077    23
17      1225    26
18      804     13
19      1307    32
20      933     20
21      737     17
22      1210    29
23      1024    24
24      1077    22
25      1077    26
26      714     16
27      496     10
28      1140    23
29      961     25
30      587     16
31      521     9
32      891     13
33      704     17
34      1153    22
35      1189    32
36      968     22
37      1016    26
38      663     14
39      776     20
40      1092    26
41      682     14
42      1288    30
43      937     25
44      876     16
45      955     23
46      1143    26
47      841     23
48      1251    32
49      765     20
50      1067    16
51      1215    28
52      1040    25
53      655     11
54      894     20
55      1011    24
56      926     18
57      838     23
58      1078    24
59      962     24
60      795     20

Answer 1