Question

A regression was run to determine if there is a relationship between the happiness index (y) and life expectancy in years of a given country (x).

The results of the regression were:

y=a+bx
a=0.13
b=0.198
r2=0.436921
r=0.661

(a) Write the equation of the Least Squares Regression line of the form

y= + x

(b) If a country increases its life expectancy, the happiness index will

• decrease
• increase

(c) If the life expectancy is increased by 2.5 years in a certain country, how much will the happiness index change? Round to two decimal places.



(d) Use the regression line to predict the happiness index of a country with a life expectancy of 74 years. Round to two decimal places.

Answer 1