4-23 - Use the data in Problem 4-22 and develop a regression model to predict selling price based on the square footage and number of bedrooms. Use this to predict the selling price of a 2,000-square-foot house with 3 bedrooms. Compare this model with the models in Problem 4-22. Should the number of bedrooms be included in the model? Why or why not? (All these calculations are correct!)

Selling Price($)	Square Footage	Bedrooms	Age (Years)
64,000	1,670	2	30
59,000	1,339	2	25
61,500	1,712	3	30
79,000	1,840	3	40
87,500	2,300	3	18
92,500	2,234	3	30
95,000	2,311	3	19
113,000	2,377	3	7
115,000	2,736	4	10
138,000	2,500	3	1
142,500	2,500	4	3
144,000	2,479	3	3
145,000	2,400	3	1
147,500	3,124	4	0
144,000	2,500	3	2
155,500	4,062	4	10
165,000	2,854	3	3

(y) (x1) (x2) (x1)^2 (x2)^2 | X1 *Y X2 *Y X1 X2 4 84,000 1,670 2 2,788,900 140,280,000 168,000 3,340 79,000 1,339 2 1,792,921 4 105,781,000 158,000 2,678 3 91,500 1,712 2,930,944 9 156,648,000 274,500 5,136 120,000 1,840 3 3,385,600 9 220,800,000 360,000 5,520 3 127,500 2,300 5,290,000 293,250,000 382,500 6,900 132,500 2,234 3 4,990,756 9 |o 296,005,000 397,500 6,702 3 145,000 2,234 4,990,756 9 323,930,000 435,000 6,702 3 164,000 2,377 5,650,129 9 389,828,000 492,000 7,131 155,000 2,736 4 7,485,696 16 424,080,000 620,000 10,944 168,000 2,500 3 6,250,000 9 420,000,000 504,000 7,500 172,500 2,500 4 6,250,000 16 431,250,000 690,000 10,000 11:34 PM BOY ON 100% Homework 4AM - Saved 174,000 2,479 3 6,145,441 9 431,346,000 522,000 7,437 175,000 2,400 3 5,760,000 9 420,000,000 525,000 7,200 177,500 3,124 4 9,759,376 16 554,510,000 710,000 12,496 184,000 2,500 3 6,250,000 9 460,000,000 552,000 7,500 195,500 4,062 4. 16,499,844 16 794,121,000 782,000 16,248 11:34 PM 100% Homework 4AM - Saved 195,000 2,854 3 8,145,316 9 556,530,000 585,000 8,562 y = 2,540,000 x1 = 40,861 x2 = 53 SUM = 104,365,679 SUM = 171 SUM = 6,418,359,000 SUM = 8,157,500 SUM = 131,996 X = 40,861/17IX = 53/17 = 3.117647059 2,403.588235 Y = 2,540,000/17 = 149,411.7647 xi = xi ( xi)^2 x1^2 = 104,365,679 (40,861)^2/17 = 6,152,660.118 x2^2 = 171 (53)^2/17 = 5.764705882 xi y = xi y ( xi) (y) Ex1 y = 6,418,359,000 (40,861) (2,540,000)/17 = 313,244,882.4 x2 y = 8,157,000 (53) (2,540,000)/17 = 238,176.4706 12 - 12 xi = xi - ( xi)^2 x1^2 = 104,365,679 (40,861)^2/17 = 6,152,660.118 x2^2 = 171 (53)^2/17 = 5.764705882 xi y = xi y ( xi) (y) x1 y = 6,418,359,000 (40,861) (2,540,000)/17 = 313,244,882.4 x2 y = 8,157,000 - (53) (2,540,000)/17 = 238,176.4706 x1 x2 = x1 x2 (x1) (x2) Ex1 x2 = 131,996 (40,861) (53)/17 = 4,605.823529 = b1 = (5.764705882) (313,244,882.4) (4,605.823529) (238,176.4706) (6,152,660.118) (5.764705882) (4,605.823529)^2 b1 = 708,765,823.71 14,254,665.59 = 49.72167318 b2 = ( x1^2) ( 2 y) ( x1 x2 ) ( x1 y)! ( x112) ( 2^2) - ( x1 x2)^2 - b2 = (6,152,660.118) (238,176.4706) (4,605.823529) (313,244,882.4)/(6,152,660.118) (5.764705882) (4,605.823529)^2 b2 = 2,266,222,000 / 14,254,665.59 = 158.9810708 b0 = 2,540,000/17 (49.72167318) (40,861)/17 (158.9810708) (53)/17 = 29,405.68914