7. Since the beginning of the year, the price of unleaded gasoline has been increasing at a constant rate of 2 cents per gallon per month. By June first, the price had reached $3.80 per gallon.

   1. Express the price of unleaded gasoline as a function of time and draw the graph.

   2. What was the price at the beginning of the year?

   3. What will be the price on October first?