P3.5 The sales revenue, food cost of sales, and guests served for a small fastfood carryout division of a restaurant for the past six months are given below.

For each of the six months calculate average check and average costs of sales food. Using these averages, calculate an index number. Set the index for month 1 at 100 and complete index numbers for the remaining five months. With the index numbers identified, convert sales revenue and cost of sales food from historic to current dollars.