9. [-/1 Points] DETAILS TANAPCALC10 5.2.046. MY NOTES ASK YOUR TEACHER Average Life Span One reason for the increase in human life span over the years has been the advances in medical technology. The average life span for American women from 1907 through 2007 is given by W(t) = 49.9 + 17.1 In(t) (1 s t s 6) where W(t) is measured in years and t is measured in 20-year intervals, with t = 1 corresponding to 1907.+ (Round your answers to one decimal place.) (a) What was the average life expectancy for women in 1907? yr (b) If the trend continues, what will be the average life expectancy for women in 2047 (t = 8)? yr