Final answer:
Sabrina's estimate to mow a lawn four times larger in 4 hours is not reasonable since logically it should take her 8 hours if she maintains the same mowing rate.
Step-by-step explanation:
Sabrina estimates that it will take 4 hours to mow a lawn that is 60 yards by 80 yards, given that she can mow a 30 yards by 40 yards lawn in 2 hours. To verify if the estimate is reasonable, we need to compare the areas of both lawns and see if the time taken to mow them scales proportionally. The area of the first lawn is 30 yards × 40 yards = 1200 square yards, and the area of the second lawn is 60 yards × 80 yards = 4800 square yards, which is exactly four times larger than the first lawn. If it takes Sabrina 2 hours to mow the smaller lawn, then logically it would take 2 hours × 4 = 8 hours to mow the lawn that is four times larger, assuming the rate of work remains constant. Therefore, Sabrina's estimate of 4 hours is not reasonable because it significantly underestimates the amount of time it would actually take based on her mowing rate.