Question

The least-squares regression Ime for predicting the nbeye pnce rom ue con ph y 4.8904 + 2.8678x. Predict the ribeye price in a month when the corn price was $6.40 per bushel. A)$12.79 per Ib B)$15.30 per lb 9$13.46 per lb D) $18.35 10) For the following data set, compute the coefficient of determination. x 3 7 1 4 6 2 V9 20 21 19 22 12 A) 0.835 B) 0.594 C) 0.165 D) 0.406 11) For the following data set, how much of the variation in the outcome variable is exp least-squares regression line? y 24 17 10 18 20 23 A)31,1% B) 90.3% C) 68.9% D) 9.7% Pationt: Mr. Colby Smith

#10 and #11

Answer 1

Ans:

10)

	x	y	xy	x^2	y^2
1	3	9	27	9	81
2	7	20	140	49	400
3	1	21	21	1	441
4	4	19	76	16	361
5	6	22	132	36	484
6	2	12	24	4	144
Total	23	103	420	115	1911

Correlation coefficient,r=(6*420-23*103)/sqrt((6*115-23^2)*(6*1911-103^2))=0.4065

Coefficient of determination,r^2=0.4065^2=0.165

Option C is correct.

11)

	x	y	xy	x^2	y^2
1	3	24	72	9	576
2	7	17	119	49	289
3	1	10	10	1	100
4	5	18	90	25	324
5	8	20	160	64	400
6	4	23	92	16	529
Total	28	112	543	164	2218

Correlation coefficient,r=(6*543-28*112)/SQRT((6*164-28^2)*(6*2218-112^2))=0.3121

Coefficient of determination,r^2=0.3121^2=0.097

So,correct option is D (9.7%)