The store is selling lemons at $0.74 each. each lemon yields about 2 tablespoons of juice. how much will it cost to buy enough lemons to make three 9-inch lemon pies, each requiring half a cup of lemon juice?

1 cup of lemon juice requires around 16 tablespoons of of juice.

First, we need to know how many cups does making 4 pies require knowing that 1 pie requires half a cup. We can simply do that using cross multiplication as follows:
number of cups = (4 * (1/2))/1 = 2 cups

Then we need to know how many tablespoons do 2 cups require knowing that each cup requires 16 tablespoons. Again we can calculate this using cross multiplication as follows:
number of tablespoons = (2*16)/1 = 32 tablespoons

Now, we know that each 1 lemon yields 2 tablespoons, we can know how many lemons needed by using cross multiplication as follows:
number of lemons = (32*1) / 2 = 16 lemons

One lemons is $0.74
Therefore,
total cost = 0.74 * 16 = 11.84$