Question

How much should a healthy Shetland pony weigh? Let x be the age of the pony (in months), and let y be the average weight of the pony (in kilograms).

x	3	6	12	18	23
y	60	95	140	162	181

(c) Use a calculator to verify that

x = 62,

x² = 1042,

y = 638,

y² = 91,230,

and

xy = 9,509.

Compute r. (Round your answer to three decimal places.) ______?

b).Fuming because you are stuck in traffic? Roadway congestion is a costly item, both in time wasted and fuel wasted. Let x represent the average annual hours per person spent in traffic delays and let y represent the average annual gallons of fuel wasted per person in traffic delays. A random sample of eight cities showed the following data.

x (hr)	29	5	18	37	22	25	15	5
y (gal)	48	3	32	53	31	38	26	9

Verify that Σx = 156, Σx² = 3918, Σy = 240, Σy² = 9308, and Σxy = 6011.

Compute r.____________?

Answer 1

Solution

( c ) :

x be the age of the pony (in months)

y be the average weight of the pony (in kilograms).

From table

x = 62

xy = 9,509

y² = 91,230

y = 638

x² = 1042 All are correct. Hence All calculations are verified and correct.

Using correlation formula r,

Here n = 5

r = 0.975

( b ) :

from above table,

Σx = 156, Σx² = 3918, Σy = 240, Σy² = 9308, and Σxy = 6011

All are correct. Hence All calculations are verified and correct.

Using correlation formula r,

Here n = 8

r = 0.979