Question

A Regression Model. A researcher wants to develop a model relating the gestation period of an animal, G, and its life expectancy, L. The table, showing gestation period in days and life expectancy in years, summarizes the results.

a) Find the line of best fit that predicts L from G (round the coefficients to two decimal places)

Animal Gestation (G). Expectancy (4)

Bear. 210. 18

Cat. 61. 15

Chicken. 22. 6

Chipmunk 31. 6

Dog. 64. 13

Elephant. 645. 35

Gorilla. 257. 30

Horse. 336. 20

Kangaroo. 42. 7

Lion. 108. 10

Squirrel. 35. 10

Tiger. 109. 16

b) Interpret the slope of the line (including units.)

c) What is the expected gestation period for an animal with a life expectancy of 9 years?

d) The human gestation period is about 280 days; what does this model predict for human life expectancy? Comment on your result.

Answer 1

y^ = 8.29 + 0.045 * x

b)

slope of 0.045035 implies that for every 1 unit increase in Gestation (x), we expect an increase of 0.045035 in Expectancy

c)

y^ = 9

9 = 8.29 + 0.045035 * x

x = 15.7655

d)

y^ = 8.29 + 0.045035 *280

= 20.8998

this model may not be valid

because hman beings manage to extend their lives by living in a civilized society