A gift box is in the shape of a trapezoidal prism with base lengths of 7 inches and 5 inches and a height of 4 inches. The height of the gift box is 8 inches. What is the volume of the gift box?

First of all there are multiple formula's to get the volume of a trapezoidal prism:

V = (1/2 * (base1 + base2) * h) * height prism

Using the numbers you gave:

base1 = 7 base2 = 5 h = 4 height prism = 8

Putting this into the equation: V = (1/2 * (7 + 5) * 4) * 8

V = (1/2 * 12 * 4) * 8

V = 24 * 8

V = 192

The volume of the gift box is 191 inches squared.