Joe is considering installing solar panels on the roof of his home, in Sun City, Arizona. If he goes forward, he will pay the installation firm but will save money on its electric bill. The amount he will save depends upon the amount of sun that Sun City will receive in the future, but he is not sure how many days of sun will occur. Draw an influence diagram. Now suppose that another uncertainty is present: Joe is not sure how much the electric utility will pay for the power that is generated by the solar panels. Draw a revised diagram.