Complete question :
The regression equation y = 4x + 20 approximates the number of people attending a picnic, y, given the number of flyers used to advertise it, x.
Which statement is true?
a.) For every extra person attending a picnic, the number of flyers used to advertise it increases by 20.
b.) For every extra person attending a picnic, the number of flyers used to advertise it increases by 4.
c.) For every extra flyer used in advertising, the attendance increases by 20 people.
d.) For every extra flyer used in advertising, the attendance increases by 4 people.
Answer: d.) For every extra flyer used in advertising, the attendance increases by 4 people.
Explanation:
Given the regression equation; y = 4x + 20;
Where y = number of people attending a picnic
x = number of flyers used to advertise it
In the equation;
y = predicted variable ; x = predictor variable ; gradient or slope = 4
The slope or gradient is the rate of change un the response variable with respect to a unit change in the independent variable.
Here, the slope value is +4 and is thus interpreted to mean that, for each 1 unit change in the independent variable (number of flyers shared), there is a corresponding increase in the response variable (number of attendees) by a unit of 4.