Justin’s doctor said that the expression StartFraction x + y + 5 over 2 EndFraction, where x and y are his parents’ current heights in inches, gives an estimate of how tall Justin will be as an adult. Justin’s work evaluating the formula is shown below. Mom’s height = 54 inches
Dad’s height = 71 inches

StartFraction 71 + 54 + 5 over 2 EndFraction = 71 + 27 + 5 = 103 inches

What error did Justin make?
He should have made x equal 54 and y equal 71.
He should have added the values in the numerator before dividing by 2.
He should have divided the 71 by 2 instead of the 27.
He should have made the numerator 76 + 59.