The monthly Medicare Part B health-care premium for most beneficiaries ages 65 and older has increased significantly since 1975. The monthly premium has increased from about $7 in 1975 to $110.50 in 2011 (Source: Centers for Medicare and Medicaid Services). The following exponential function models the premium increases:
M(x) = 7(1.080)x
Where x is the number of years since 1975 Estimate the monthly Medicare Part B premium in 1985, in 1992, and in 2002 Round to the nearest dollar