Answer:
If an equal number of each brand was ordered, how many dozens of each brand were ordered?
Step-by-step explanation:
in order to determine the number of balls purchased, we must first determine the difference in price between them = $2 - $0.90 = $1.10
since the total difference in price was $660 and an equal number of balls were purchased, then the number of balls purchased = $660 / $1.10 = 600 balls
to determine the number of dozens purchased of each brand we just divide 600 by 12 = 50 dozens
There is nothing wrong with Arlene's math. Her answer is correct. The mistake is that she has cited the "associative property" where the "commutative property" should have been cited, and vice versa.
The associative property has to do with where you put parentheses. The commutative property has to do with what order the operands are in.
A[n] = (a[n-1] +a[n+1])/2 = (3.9 +7.1)/2 = 11/2 = 5.5