1.28. A midwestern university has three types of health plans: a health main- tenance organization (HMO), a preferred provider organization (PPO), and a traditional fee for service plan (FFS). Experience dictates that people change plans according to the following transition matrix HMO PPO FFS HMO .85 .1 .05 PPO .2 FFS .1 73 . .1 3 .6 1.12. EXERCISES 67 In 2000, the percentages for the three plans were HMO:30%, PPO:25%, and FFS:45%. (a) What will be the percentages for the three plans in 2001? (b) What is the long run fraction choosing each of the three plans? 1. Consider the signal x(1) 1, -21