The Larsons (from Exercise 2) decided they would not use the September amounts, when they were on vacation, nor the December amounts, when cousins stayed with them. Assume the chart is a spreadsheet with row 1 as the month labels and column A as the expense categories.
a. Write a spreadsheet formula to calculate the adjusted average for food.
b. What is the adjusted average for food?
c. Write a spreadsheet formula to calculate the adjusted average for electricity.
d. What is adjusted average for electricity?
e. Why do you think that the adjusted average is not that far off from the six-month average in each category?