15.TheSocial Security Administration uses a linear growth model to estimate life expectancy in the United States. The model uses the explicit formulaL_N =66.17 + 0.96 N whereL_N is the life expectancy of a person born in the year 1995 +Ni.eN= 0corresponds to 1995 as the year of birth,N=1corresponds to 1996 as the year of birth, and so on.(Source:Social Security Administration, www.socialsecurity.gov.)

a)Assuming the model continues to work indefinitely, estimate the life expectancy of a person born in 2012. Report your answer to 2 decimal places. Answeryears

b)Assuming the model continues to work indefinitely, what year will you have to be born so your life expectancy is 90? Answer