A peanut vendor has initial start up costs of $7600 and variable costs of $0.70 per bag of peanuts.

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A peanut vendor has initial start up costs of $7600 and variable costs of $0.70 per bag of peanuts. What is the cost function?

We set up the cost function C(b) where b is the number of bags:
C(b) = Cost per bag * b + Start up costs

Plugging in our numbers, we get:
C(b) = 0.70b + 7600