Answer:
1 1/3 inches
Explanation:
The formula for the surface area of the prism can be written as ...
A = 2(lw +h(l+w))
Filling in the given values and solving for h, we find ...
68 2/3 = 2(3·7 + h(3+7))
68 2/3 = 42 +20h . . . . eliminate parentheses
26 2/3 = 20h . . subtract 42
1 1/3 = h . . . . . . . divide by 20
The height of the prism is 1 1/3 inches.