Final answer:
Setting up and solving a proportion to find the cost of 6 apples.
Step-by-step explanation:
To find the cost of 6 apples, let's set up a proportion using the given information. We know that 4 apples cost $0.80, so the cost of 1 apple is $0.80/4 = $0.20. Now we can set up the proportion: 4 apples / $0.80 = 6 apples / X. Cross multiplying, we get 4X = 6 * $0.80. Simplifying, we find that X = $1.20. Therefore, the cost of 6 apples is $1.20.