The future of Social Security and Medicare generates a lot of debate and political posturing. Analysts predict that without significant change, Social Security and Medicare funds will be exhausted at some future date (the date depends on the expert). The next two exercises ask you to use linear trends based on Social Security Administration historical data in order to estimate when, if ever, the funds will be in trouble (i. e., when disbursements will exceed income). Social Security income for the years 1990–2000 suggest that the income trend can be estimated by the equation
y = 21.27x 1 264.70
where x is the number of years since 1990 and y = annual income in billions of dollars. For the same years, the Social Security disbursements have the linear trend
y = 13.29x + 226.53

Required:
a. Find the point where income = disbursements.
b. Does this suggest that Social Security is going broke?
c. What other factors might influence the trend that would cause it to deviate from the linear trend?