Answer:
When x1 and x2 decrease 4 units, y decreases by 20 units
Step-by-step explanation:
The regression model is
We have to calculate y for a decrease of 4 units in x1 and x2. For this we have to calculate the variation of y in function of x1 and x2.
As it is a linear regression model, we have:
For a variation in 4 units of x1 and x2, we have