In: Psychology
After watching the Superbowl, Steve is convinced that the referees are often blind, blowing calls that greatly influence teams’ chances of winning. To test his idea, Steve chooses ten NFL teams at random and watches every single game in a season for those ten teams. He records the number of blown calls going against each team (regardless of whether he is a fan of the team!). He also records the winning percentages of each of those ten teams at the end of the season. He is most interested in knowing whether the number of blown calls going against each team predicts those teams’ winning percentages. Using Steve’s dataset below, provide your hand calculations to answer the questions that follow.
Blown Calls (X) |
Winning Percentage (Y) |
X2 |
Y2 |
XY |
|
50 |
78 |
2500 |
6084 |
3900 |
|
61 |
83 |
3721 |
6889 |
5063 |
|
66 |
55 |
4356 |
3025 |
3630 |
|
69 |
73 |
4761 |
5329 |
5037 |
|
73 |
49 |
5329 |
2401 |
3577 |
|
74 |
59 |
5476 |
3481 |
4366 |
|
79 |
39 |
6241 |
1521 |
3081 |
|
80 |
45 |
6400 |
2025 |
3600 |
|
85 |
47 |
7225 |
2209 |
3995 |
|
110 |
32 |
12100 |
1024 |
3520 |
|
Total |
747 |
560 |
58109 |
33998 |
39769 |
Steve’s favorite team had only 60 blown calls against them this season. What would you predict Steve’s team’s winning percentage to be?
Blown Calls (X) |
Winning Percentage (Y) |
X2 |
Y2 |
XY |
|
50 |
78 |
2500 |
6084 |
3900 |
|
61 |
83 |
3721 |
6889 |
5063 |
|
66 |
55 |
4356 |
3025 |
3630 |
|
69 |
73 |
4761 |
5329 |
5037 |
|
73 |
49 |
5329 |
2401 |
3577 |
|
74 |
59 |
5476 |
3481 |
4366 |
|
79 |
39 |
6241 |
1521 |
3081 |
|
80 |
45 |
6400 |
2025 |
3600 |
|
85 |
47 |
7225 |
2209 |
3995 |
|
110 |
32 |
12100 |
1024 |
3520 |
|
Total |
747 |
560 |
58109 |
33998 |
39769 |
using this data
we can calculate the regression intercept (a) and then on the basis of that we can it to find y for a certain value of x
Now we calculate the slope
Now for calculating y we calculate b
Now we calculate y by using the formula
Y=mX+b
Y= (0.454) ( 60) + (22.087)
Y= 27.24+22.087
Y= 49.327
Hence3, the winning percentage against 60 blown calls can be predicted to be 49.327