Question

you are the foreman of the Bar-S cattle ranch in Colorado. A neighboring ranch has calves for sale, and you are going to buy some calves to add to the Bar-S herd. How much should a healthy calf weigh? Let x be the age of the calf (in weeks), and let y be the weight of the calf (in kilograms).

x	3	4	12	16	26	36
y	43	54	71	100	150	200

Complete parts (a) through (e), given Σx = 97, Σy = 618, Σx² = 2397, Σy² = 82,306, Σxy = 13,897, and r ≈ 0.993.

(b) Verify the given sums Σx, Σy, Σx², Σy², Σxy, and the value of the sample correlation coefficient r. (Round your value for r to three decimal places.)

Σx =
Σy =
Σx2 =
Σy2 =
Σxy =
r =

(c) Find x, and y. Then find the equation of the least-squares line  = a + bx. (Round your answers for x and y to two decimal places. Round your answers for a and b to three decimal places.)

x	=
y	=
(y hat)	=	+  x

Answer 1

The statistical software output for this problem is:

Hence,

Σx = 97

Σy = 618

Σx² = 2397

Σy² = 82,306

Σxy = 13,897

r = 0.993.

c) x = 97/6 = 16.16

y = 618/6 = 103

y - hat = 26.812 + 4.713 x