In: Math
Create an excel worksheet and populate it, in columns, with values of X that are -2, -1, 0, 1, 2 and values of Y that are -1, 1,1,1,3. As an aside, note that the sample mean of X is 0. Create the columns shown below, and enter the proper formulas into excel.
(X minus |
(X minus mean) |
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Mean) |
times (Y |
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Y |
Y-mean |
X |
X-mean |
squared |
minus mean) |
Y-hat |
u-hat |
|
-1 |
-2 |
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1 |
-1 |
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1 |
0 |
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1 |
1 |
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3 |
2 |
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sum |
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sum*1/n |
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B1-hat = |
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B0-hat = |
(X minus | (X minus mean) | |||||||||
Mean) | times (Y | |||||||||
Y | Y-mean | X | X-mean | squared | minus mean) | Y-hat | u-hat | (x-mean)(y-mean) | ||
-1 | -2 | -2 | -2 | 4 | 4 | 4 | ||||
1 | 0 | -1 | -1 | 1 | 0 | 0 | ||||
1 | 0 | 0 | 0 | 0 | 0 | 0 | ||||
1 | 0 | 1 | 1 | 1 | 0 | 0 | ||||
3 | 2 | 2 | 2 | 4 | 4 | 4 | ||||
sum | 5 | 0 | 0 | 0 | 10 | 8 | 1 | 0 | 8 | |
sum*1/n | 1 | 0 | 0 | 0 | 2 | 1.6 | ||||
B1-hat = | 0.8 | |||||||||
B0-hat = | 1 |
Formulas used are: