The monthly expenditure of September for question 9 and 10 are respectively $107.91 and $19892.25
From the question, it is rather easy to figure out. We are given expenditures from May through August, September missing but we are also provided with the average expenditure.
We know that the average expenditure is given as
sum of expenditure of all the months / number of months
So, for number 9, we have
[(112.11 + 97.13 + 106.45 + 121.85 + x) / 5] = 109.09
(437.54 + x) / 5 = 109.09....... if we cross multiply
437.54 + x = 109.09 * 5
437.54 + x = 545.45
x = 545.45 - 437.54
x = 107.91
And for number 10, we have
[(23687.12 + 19871.03 + 20056.90 + 24510.30 + y) / 5] = 21603.52
(88125.35 + y) / 5 = 21603.52......... if we cross multiply
88125.35 + y = 21603.52 * 5
88125.35 + y = 108017.6
y = 108017.6 - 88125.35
y = 19892.25
to learn more, see https://brainly.com/question/24090351
