You want to find the monthly average over the past 6 months.
July: $78.56
August: $30.21
September: $81.20
October: $79.08
November: $66.18
December: $100.75
Add all of these up
(July) $78.56
(August) $30.21
(September) $81.20
(October) $79.08
(November) $66.18
(December) + $100.75
----------------------------------------------
(Total cost) $435.88
There are 6 months you are calculating for, therefore divide the total (combined) cost of 6 months with the total number of months (in this case, 6)
$435.88 (total cost of 6 months) ÷ 6 (months)
The average cost per month of over the past 6 months is $72.66.
To find the monthly average (mean), add all the numbers up and divide the answer by the total number of numbers you added up.
July: $78.56
August: $30.21
September: $81.20
October: $79.08
November: $66.18
December: $100.75
Add all the bills up.
$78.56 +
$30.21 +
$81.20 +
$79.08 +
$66.18 +
$100.75 =
$435.98
Divide $435.98 by 6 (because you added up 6 numbers).
$435.98 ÷ 6 = $72.66
[tex]\boxed {D)~72.66~is~your~answer.} [/tex]
