Respuesta :
Given:
The expression is which gives an estimate of how tall Justin will be as an adult is
[tex]\dfrac{x+y+5}{2}[/tex]
where, x and y are his parents’ current heights in inches.
Mom’s height = 54 inches Dad’s height = 71 inches.
His calculation:
[tex]\dfrac{71+54+5}{2}=71+27+5=103\ inches[/tex]
To find:
Justin's mistake.
Solution:
Let x be Dad’s height  and y be Mom’s height. So, correct estimation for his height is
[tex]\dfrac{71+54+5}{2}=\dfrac{130}{2}[/tex]
[tex]\dfrac{71+54+5}{2}=65[/tex]
He should have added the values in the numerator before dividing by 2.
Therefore, the correct option is B.
