Suppose that the bike shop offers two different models for sale: basic ($120) and deluxe ($150). Past experiences indicate that sales of the basic model will have a mean of 5.4 bikes with a standard deviation of 1.2, and sales of the deluxe model will have a mean of 3.2 with a standard deviation of 0.8. The cost of setting up for the sidewalk sale is $200.

What are the random variables in this case? Define them, and use them to express the bicycle shop's net income.