I am asked to create an objective function of the problem below. Please, how can I move from here.

Compute the total cost of each food type by multiplying the Price column of the table food and the optimization variable servings. Name the resulting optimization expression C. Make sure to use element-wise operator .* when performing the multiplication.

I have tried this:

c = food.Price.*(servings), but the answer is not right.

[Dyuman Joshi]

What exactly does it mean by "optimization variable"?

Also, can you attach your data?