Question

Given a regression equation Y = 77.23 - .277(X1), where X1 = IMR (infant mortality rate, measured as the number of deaths per 1,000 births), which of the following is true?

A) When life expectancy increases by 1 year, IMR decreases by .277

B) When IMR increases by 1 per thousand, life expectancy increases by .277 years

C) When life expectancy decreases by 1 year, IMR decreases by .277

D) When IMR increases by 1 per thousand, life expectancy decreases by .277 years

Answer 1

The Regression Equation is Y = 77.23 - .277 X1

where

Y =Life expectancy in years

X1 = Infant Mortality (Deaths per 1000 births)

Here Y is the dependent variable and X1 is the variable which is being used to predict Y.

Hence A is not possible because here Y is being used to predict X1

Option B is also not possible as when Infant Mortality Increases by 1 Life Expectancy is reduced by 0.277 years whereas here it is increasing.

Option C is also not possible as here also both are moving in the same direction.

Option D is therefore the correct option.