Question

Suppose x represents the size of the caribou population (in hundreds) and y represents the size of the wolf population in Denali National Park.

x 30 34 27 25 17 23 20

y 66 79 70 60 48 55 60

a) Given that x ̄ = 25.1429, y ̄ = 62.5714, sx = 5.8146, sy = 10.1630, and r = .9150, find the least squares regression line, yˆ = b1x + b0.

Round each number to 4 decimal place

Predict what the population of wolves would be if the population of caribou is 19 (in hundreds). Round to the nearest whole number.

Is it acceptable to use yˆ to predict how many wolves would be in Denali if the number of caribou is 150? (Yes or No) Why or why not?

Answer 1

from above

a)

y^ =22.3606+1.5993*x

b)

predicted val=22.3606+1.5993*19=

53

c)

No since 150 falls outside the range of x values therefore it is not acceptable to predict y^ on basis of above regression equation,