P3.5 The sales revenue, food cost of sales, and guests served for a small fast-food carryout division of a restaurant for the past six months are given as follows: Month Sales Revenue Cost of Guests Sales, Food Served 1 $258,200 $ 96,200 10,200 2 274,800 104,300 10,400 3 285.600 110,500 10,300 4 289,400 113,100 10,100 5 298,300 118,900 10,400 304,600 123,700 10,500 For each of the six months: a. Calculate average check and average costs of sales food. b. Using these averages, calculate a trend index number. Set the trend in- dex for month 1 at 100% (or 100) and complete trend index numbers for the remaining five months. c. With the index numbers identified, convert sales revenue and cost of sales food from historic to current dollars. d. Comment on the results of your calculations of the three requirements for the six months