The average cost of 5 items is $316.05. The first four items cost $48.20, $40.60, $63.75, and $70.15. Find the cost of the fifth item.
Add all the prices of the four items, then subtract the total from $316.05. What's left is the answer: $93.35
1357.55 is the correct answer :)
Let A = average f. = cost of 5th item316.05=(48.20+40.60+63.75+70.15+f)/5I'll finish in Comments.