A regression analysis was done of residential property values in a portion of a city. The dependent variable is Sale Price (Y) and the independent variable is Square Footage (X). Data for 157 properties were used in the regression. The results are listed below.
Predicted Y = 96,600 + 22.5(X) R-square = .77
What is the predicted value of Sale Price if the property has 2500 square feet?

A. $56,250.00
B. $152,850.00
C. $96,622.50
D. $96,600.00

Respuesta :

Answer:

[tex] Y= 96600+ 22.5*2500= 152850[/tex]

So then the correct option for this case would be:

B. $152,850.00

Step-by-step explanation:

They adjust a linear model [tex] y = mx +b[/tex] using the least squares method

For this case we assume that they calculate the slope with the following formula:

[tex]m=\frac{S_{xy}}{S_{xx}}[/tex]

Where:

[tex]S_{xy}=\sum_{i=1}^n x_i y_i -\frac{(\sum_{i=1}^n x_i)(\sum_{i=1}^n y_i)}{n}[/tex]

[tex]S_{xx}=\sum_{i=1}^n x^2_i -\frac{(\sum_{i=1}^n x_i)^2}{n}[/tex]

[tex] \bar X =\frac{\sum X}{n}[/tex]

[tex] \bar Y =\frac{\sum Y}{n}[/tex]

And we can find the intercept using this:

[tex]b=\bar y -m \bar x[/tex]

After apply the method they obtain the following regression equation:

[tex] Y = 96600 + 22.5 X[/tex]

Where Y represent the sale price and X the square footage.

And we want to estimate the predicted value of Sale price if the property has a 2500 square footage.

So for this case we just need to replace into our original equation the value of X = 2500 and we got:

[tex] Y= 96600+ 22.5*2500= 152850[/tex]

So then the correct option for this case would be:

B. $152,850.00