Refer to the Real Estate data. Use the selling price of the home as the dependen
ID: 3157906 • Letter: R
Question
Refer to the Real Estate data. Use the selling price of the home as the dependent variable and determine the regression equation with the numbers of bedrooms, size of the house, whether there is a pool, distance from the center of the city, township, whether there is an attached garage, and the number of bathrooms as independent variables.
Write out the regression equation. How much does a garage or an extra bathroom add to the selling price of a home?
Determine the value of R-squared. Provide an interpretation of the variance R-squared represents.
Develop a correlation matrix. Which independent variables have strong or weak correlations with the dependent variable (price)?
Price Bedrooms Square Feet Pool Distance Township Garage Baths 245,400 2 2100 0 12 1 1 2 221,100 3 2300 0 18 1 0 1.5 232,200 3 1900 0 16 1 1 1.5 198,300 4 2100 0 19 1 1 1.5 192,600 6 2200 0 14 1 0 2 147,400 6 1700 0 12 1 0 2 224,000 3 1900 0 6 1 1 2 220,900 2 2300 0 12 1 1 2 199,000 3 2500 0 18 1 0 1.5 139,900 2 2100 1 28 1 0 1.5 224,800 3 2200 1 17 1 1 2.5 216,800 3 2200 1 15 1 1 2 176,000 4 2200 1 15 1 1 2 189,400 4 2200 1 24 1 1 2 125,900 2 2400 1 28 1 0 1.5 192,900 4 1900 0 14 2 1 2.5 166,200 3 2000 0 16 2 1 2 307,800 3 2400 0 21 2 1 3 209,700 5 2200 0 13 2 1 2 207,500 3 2100 0 10 2 0 2 209,700 4 2200 0 19 2 1 2 173,600 4 2100 0 14 2 1 2.5 188,300 6 2100 0 14 2 1 2.5 213,600 2 2200 1 16 2 0 2.5 271,800 2 2100 1 9 2 1 2.5 281,300 3 2100 1 16 2 1 2 247,700 5 2400 1 16 2 1 2 216,000 4 2300 1 19 2 0 2 273,200 5 2200 1 16 2 1 3 251,400 3 1900 1 12 2 1 2 154,300 2 2000 1 13 2 0 2 294,000 2 2100 1 13 2 1 2.5 192,200 2 2400 1 16 2 0 2.5 244,600 2 2300 1 9 2 1 2.5 253,200 3 2300 1 16 2 1 2 172,700 4 2200 0 16 3 0 2 206,000 3 2100 0 9 3 0 1.5 166,500 3 1600 0 19 3 0 2.5 190,900 3 2200 0 18 3 1 2 254,300 4 2500 0 15 3 1 2 176,300 2 2000 0 17 3 0 2 155,400 4 2400 0 16 3 0 2 242,100 3 2300 1 12 3 0 2 327,200 6 2500 1 15 3 1 2 292,400 4 2100 1 14 3 1 2 246,100 4 2100 1 18 3 1 2 194,400 2 2300 1 11 3 0 2 233,000 3 2200 1 14 3 1 1.5 234,000 2 1700 1 19 3 1 2 199,800 3 2100 1 19 3 1 2 236,400 5 2200 1 20 3 1 2 172,400 3 2200 1 23 3 0 2 246,000 6 2300 1 7 3 1 3 312,100 7 2400 1 13 3 1 3 289,800 6 2000 1 21 3 1 3 217,800 3 2500 1 12 3 0 2 294,500 6 2700 1 15 3 1 2 263,200 4 2300 1 14 3 1 2 221,500 4 2300 1 18 3 1 2 175,000 2 2500 1 11 3 0 2 207,500 5 2300 0 21 4 0 2.5 198,900 3 2200 0 10 4 1 2 209,300 6 1900 0 15 4 1 2 182,700 4 2000 0 14 4 0 2.5 205,100 3 2000 0 20 4 0 2 175,600 4 2300 0 24 4 1 2 171,600 3 2000 0 16 4 0 2 269,900 5 2200 0 11 4 1 2.5 186,700 5 2500 0 21 4 0 2.5 179,000 3 2400 0 10 4 1 2 188,300 6 2100 0 15 4 1 2 182,400 4 2100 1 19 4 0 2 266,600 4 2400 1 13 4 1 2 209,000 2 1700 1 8 4 1 1.5 270,800 6 2500 1 7 4 1 2 252,300 4 2600 1 8 4 1 2 345,300 8 2600 1 9 4 1 2 187,000 2 1900 1 26 4 0 2 257,200 2 2100 1 9 4 1 2 294,300 7 2400 1 8 4 1 2 125,000 2 1900 1 18 4 0 1.5 164,100 4 2300 1 19 4 0 2 240,000 4 2600 1 13 4 1 2 188,100 2 1900 1 8 4 1 1.5 243,700 6 2700 1 7 4 1 2 227,100 4 2900 1 8 4 1 2 310,800 8 2900 1 9 4 1 2 179,000 3 2400 1 8 4 1 2 173,600 4 2100 1 9 4 1 2 263,100 4 2300 0 17 5 1 2 173,100 2 2200 0 21 5 1 1.5 236,800 4 2600 0 17 5 1 2 209,300 5 2100 1 20 5 0 1.5 326,300 6 2100 1 11 5 1 3 180,400 2 2000 1 11 5 0 2 207,100 2 2000 1 11 5 1 2 177,100 2 1900 1 10 5 1 2 312,100 6 2600 1 7 5 1 2.5 269,200 5 2200 1 8 5 1 3 228,400 3 2300 1 17 5 1 1.5 222,100 2 2100 1 9 5 1 2 188,300 5 2300 1 20 5 0 1.5 293,700 6 2400 1 11 5 1 3 227,100 4 2900 1 20 5 0 1.5 188,300 5 2300 1 11 5 1 3Explanation / Answer
Refer to the Real Estate data. Use the selling price of the home as the dependent variable and determine the regression equation with the numbers of bedrooms, size of the house, whether there is a pool, distance from the center of the city, township, whether there is an attached garage, and the number of bathrooms as independent variables.
Write out the regression equation. How much does a garage or an extra bathroom add to the selling price of a home?
Regression Analysis
R²
0.534
Adjusted R²
0.500
n
105
R
0.730
k
7
Std. Error
33310.645
Dep. Var.
Price
ANOVA table
Source
SS
df
MS
F
p-value
Regression
123,136,480,136.3900
7
17,590,925,733.7700
15.85
1.01E-13
Residual
107,631,109,006.4670
97
1,109,599,061.9223
Total
230,767,589,142.8570
104
Regression output
confidence interval
variables
coefficients
std. error
t (df=97)
p-value
95% lower
95% upper
Intercept
43,137.2499
39,739.2782
1.086
.2804
-35,734.2170
122,008.7167
Bedrooms
7,375.4976
2,590.0212
2.848
.0054
2,235.0226
12,515.9727
Square Feet
38.6270
14.7546
2.618
.0103
9.3431
67.9108
Pool
19,111.4418
7,126.5527
2.682
.0086
4,967.2074
33,255.6762
Distance
-1,012.6688
741.3847
-1.366
.1751
-2,484.1123
458.7746
Township
-1,739.0078
2,699.4164
-0.644
.5210
-7,096.6020
3,618.5864
Garage
35,498.0189
7,675.8385
4.625
1.16E-05
20,263.6043
50,732.4335
Baths
23,092.5459
9,058.3077
2.549
.0124
5,114.3125
41,070.7792
Price = 43,137.2499 +7,375.4976 *Bedrooms+ 38.6270 *Square Feet+ 19,111.4418 *Pool -1,012.6688 *Distance -1,739.0078 *Township+ 35,498.0189 *Garage+ 23,092.5459 *Baths
Presence of garage in the home increases the price by $35,498.0189.
If one bath room increases in the home will increase the price by $23,092.5459.
Determine the value of R-squared. Provide an interpretation of the variance R-squared represents.
R-squared =0.534
53.4% of variance in price is explained by the model.
Develop a correlation matrix. Which independent variables have strong or weak correlations with the dependent variable (price)?
Correlation Matrix
Price
Bedrooms
Square Feet
Pool
Distance
Township
Garage
Baths
Price
1.000
Bedrooms
.467
1.000
Square Feet
.371
.383
1.000
Pool
.294
.005
.201
1.000
Distance
-.347
-.153
-.117
-.139
1.000
Township
.128
.200
.185
.201
-.209
1.000
Garage
.526
.234
.083
.114
-.359
.057
1.000
Baths
.382
.329
.024
.055
-.195
.050
.221
1.000
105
sample size
± .192
critical value .05 (two-tail)
Correlation between Price and Garage is strong, r=0.526.
Correlation between Price and Township is weak, r=0.128.
Regression Analysis
R²
0.534
Adjusted R²
0.500
n
105
R
0.730
k
7
Std. Error
33310.645
Dep. Var.
Price
ANOVA table
Source
SS
df
MS
F
p-value
Regression
123,136,480,136.3900
7
17,590,925,733.7700
15.85
1.01E-13
Residual
107,631,109,006.4670
97
1,109,599,061.9223
Total
230,767,589,142.8570
104
Regression output
confidence interval
variables
coefficients
std. error
t (df=97)
p-value
95% lower
95% upper
Intercept
43,137.2499
39,739.2782
1.086
.2804
-35,734.2170
122,008.7167
Bedrooms
7,375.4976
2,590.0212
2.848
.0054
2,235.0226
12,515.9727
Square Feet
38.6270
14.7546
2.618
.0103
9.3431
67.9108
Pool
19,111.4418
7,126.5527
2.682
.0086
4,967.2074
33,255.6762
Distance
-1,012.6688
741.3847
-1.366
.1751
-2,484.1123
458.7746
Township
-1,739.0078
2,699.4164
-0.644
.5210
-7,096.6020
3,618.5864
Garage
35,498.0189
7,675.8385
4.625
1.16E-05
20,263.6043
50,732.4335
Baths
23,092.5459
9,058.3077
2.549
.0124
5,114.3125
41,070.7792