In: Statistics and Probability
One of the questions most frequently asked by prospective home buyers along the east coast of the United States is: | ||||
If we purchase this home, how much can we expect to pay to heat it during the winter? The research department | ||||
at Herrington Real Estate has collected the following information. Temperature = Mean Outside Temperature (F); | ||||
Attic = Attic insulation (in inches). | ||||
Home | Mean Outside Temperature (degrees) | Attic Insulation (inches) | Monthly Heating Costs ($) | |
1 | 18 | 3 | 188 | |
2 | 34 | 2 | 256 | |
3 | 36 | 7 | 127 | |
4 | 60 | 6 | 239 | |
5 | 65 | 5 | 190 | |
6 | 20 | 5 | 180 | |
7 | 10 | 6 | 210 | |
8 | 7 | 9 | 260 | |
9 | 21 | 4 | 255 | |
10 | 35 | 6 | 160 | |
11 | 54 | 12 | 100 | |
12 | 26 | 8 | 105 | |
13 | 25 | 3 | 375 | |
14 | 39 | 4 | 250 |
What is the estimate for monthly heating costs with a mean outside temperature of 45 degrees and 4 inches of attic | ||||
insulation? ( WATCH YOUR UNITS! | ||||
According to your equation, holding the amount of attic insulation constant, for each one degree increase in the | ||||
mean outside temperature, monthly heating costs (increase/ do not change / decrease) by __________________. | ||||
Round Correctly and include the units! | ||||
According to your equation, holding the mean outside temperature size constant, for every one inch increase in the | ||||
amount of insulation, monthly heating costs (increase / do not change / decrease) by __________________________. | ||||
Round like the original data and include the units. | ||||
How much of the variability in monthly heating costs is explained by the estimated regression equation? |
What is the estimate for monthly heating costs with a mean outside temperature of 45 degrees and 4 inches of attic insulation?
y = 226.482
According to your equation, holding the amount of attic insulation constant, for each one degree increase in the mean outside temperature, monthly heating costs decrease by 0.6116.
According to your equation, holding the mean outside temperature size constant, for every one inch increase in the amount of insulation, monthly heating costs decrease by 16.0768.
How much of the variability in monthly heating costs is explained by the estimated regression equation?
38.8%
R² | 0.388 | |||||
Adjusted R² | 0.277 | |||||
R | 0.623 | |||||
Std. Error | 62.617 | |||||
n | 14 | |||||
k | 2 | |||||
Dep. Var. | Monthly Heating Costs ($) | |||||
ANOVA table | ||||||
Source | SS | df | MS | F | p-value | |
Regression | 27,331.0822 | 2 | 13,665.5411 | 3.49 | .0672 | |
Residual | 43,129.2749 | 11 | 3,920.8432 | |||
Total | 70,460.3571 | 13 | ||||
Regression output | confidence interval | |||||
variables | coefficients | std. error | t (df=11) | p-value | 95% lower | 95% upper |
Intercept | 318.3129 | |||||
Mean Outside Temperature (degre | -0.6116 | 0.9901 | -0.618 | .5493 | -2.7909 | 1.5676 |
Attic Insulation (inches) | -16.0768 | 6.5710 | -2.447 | .0324 | -30.5395 | -1.6142 |
Predicted values for: Monthly Heating Costs ($) | ||||||
95% Confidence Interval | 95% Prediction Interval | |||||
Mean Outside Temperature (degre | Attic Insulation (inches) | Predicted | lower | upper | lower | upper |
45 | 4 | 226.482 | 172.049 | 280.915 | 78.304 | 374.660 |
Please give me a thumbs-up if this helps you out. Thank you!