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 Question from Rhonda, a teacher: I help to manage a concession stand. We sell a variety of items. Some have a profit of 60%, some 80%, etc. We have done nothing scientific to choose our prices. We just try to stay in the ballpark of schools around us. Our administrator wants to pay those that run the concession stand a percent of what is in the cash box after start-up money is taken out. We have some gathered some data (not much) on how many of each item we sell and can certainly calculate percent profit. Is the profit for the entire concession stand a weighed average? I'm thinking (% profit on candy)(number candy sold) + (percent profit nachos)(number nachos sold) + (percent profit pop)(number pop sold), etc. Will this work? Does the AMOUNT of profit for these different items need to be figured-in? Hmmm. . . Thank you for a timely response.

We have two responses for you

Hi Rhonda,

Let's try an example. Suppose you sell Snickers bars for $1 and make 25% profit (25 cents) and hot dogs for$2 and make 50% profit (1 dollar). If, in a day, the sand sells 40 snickers bars and 30 hot dogs, then your formula gives:
0.25(40) + 0.5(30) = 10 + 15 = 25.

Notice that there are no dollars anywhere in there. The actual profit is 25 cents per Snickers Bar and 1 dollar per hot dog, or $10 +$30 = \$40.

So, you are right that the price of the items should be included in the formula. I would say it is:
(item 1 profit)(number of item 1 sold) + (item 2 profit)(number of item 2 sold) + etc
This is the same as (item 1 price((% profit on item 1)(number of item 1 sold) + (item 2 price)(% profit on item 2)(number of item 2 sold) + etc

Hope this helps.
Victoria

Hi Rhonda,

I want to add something to Victoria's response. You say that "Our administrator wants to pay those that run the concession stand a percent of what is in the cash box after start-up money is taken out." Is there a tax on any of the items sold? If so you probably want to remove the tax owing as well as the start-up money before calculating the pay for the workers.

I gather that this is a concession stand in a school. Is percentage part of the curriculum is any of the grades in your school? If so it might be nice to ask the students your question.

Harley

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