A multiple regression model has the form = 7 + 2 x1 + 9 x2 As x1 increases by 1 unit (holding x2 constant), y is expected to a. increase by 9 units b. decrease by 9 units c. increase by 2 units d. decrease by 2 units

triangular prism

Step-by-step explanation:

Verify each case

case 1) rectangular prism

A rectangular prism has six rectangular faces

case 2) rectangular pyramid

A rectangular pyramid has one rectangular face and four triangular faces

case 3) triangular prism

A triangular prism has three rectangular faces and two triangular faces

case 4) triangular pyramid

A triangular pyramid has four triangular faces

therefore

A triangular prism has three rectangular faces