Question

In a simple linear regression model (One independent variable), If we change the input variable by 1 unit. How much output variable will change?

(a) by 1

(b) no change

(c) by intercept

(d) by its slope

The question was asked at a job interview.

The question is from Linear Regression topic in division Commands, Packages, Visualizing Data and Linear Regression of R Programming

Answer 1

The correct answer is (d) by its slope

To explain I would say: For linear regression Y=a+bx+error. If neglect error then Y=a+bx. If x increases by 1, then Y = a+b(x+1) which implies Y=a+bx+b. So Y increases by its slope.