Estimate: 80. The answer given (78.3) is reasonable.
Work Step by Step
We need to check whether the answer given is reasonable: $395.415\div 5.05=78.3$ We estimate the answer by rounding: $395.415\div 5.05\approx 400\div 5=80$ We see that the given answer, $78.3$, and the estimate, $80$, are very close. Thus the given answer is reasonable. (We do not need to find the exact answer if the answer is reasonable.)