In: Statistics and Probability
Let assume that you are going to purchase a house you know that the more space you have the more the house is going to cost. You decide to collect some data.
square feet. Price in kilo dollars
1400.
200
1900.
245
1900.
260
2100.
300
2250.
310
1450.
190
2300.
400
3100.
525
Simple linear regression: regression between one independent variable and a single independent variable.
We can say the data has a positive correlation but what does that mean?
What would you expect to pay for a 1600 square foot house?
Solution:
We can use the excel regression data analysis tool to find the least-squares regression equation. The excel output is given below:
SUMMARY OUTPUT | ||||||
Regression Statistics | ||||||
Multiple R | 0.968968092 | |||||
R Square | 0.938899163 | |||||
Adjusted R Square | 0.92871569 | |||||
Standard Error | 29.82279427 | |||||
Observations | 8 | |||||
ANOVA | ||||||
df | SS | MS | F | Significance F | ||
Regression | 1 | 82001.10565 | 82001.10565 | 92.19832751 | 7.29798E-05 | |
Residual | 6 | 5336.394349 | 889.3990581 | |||
Total | 7 | 87337.5 | ||||
Coefficients | Standard Error | t Stat | P-value | Lower 95% | Upper 95% | |
Intercept | -107.7610565 | 44.13481929 | -2.441633573 | 0.050359792 | -215.7550687 | 0.232955652 |
Square feet | 0.200737101 | 0.020905768 | 9.601996017 | 7.29798E-05 | 0.149582529 | 0.251891672 |
Therefore, the regression equation is:
We can say the data has a positive correlation but what does that mean?
Answer: It means as the square feet for the house increases, the price in Kilo dollars also increases
What would you expect to pay for a 1600 square foot house?