Year Powerboat Manatees Year Powerboat Manatees Registration Killed Registration Killed (Thousands) (Thousands) 1977 417 13 1988 718 43 1978 429 21 1989 710 49 1979 491 24 1990 716 47 1980 506 16 1991 715 53 1981 516 24 1992 710 38 1982 526 20 1993 729 34 1983 558 15 1994 747 47 1984 585 34 1995 765 42 1985 613 33 1996 788 60 1986 644 33 1997 803 54 1987 675 39 1998 823 66a. Fit a new model to the data in question 1. This model should predict the number of manatees killed as a function of the number of powerboat registrations, the estimated size of the manatee populations, and the indicator variable you created for Law. Is power boat registration still a significant predictor of manatees killed? b. Fit the model suggested by part a (i.e. remove insignificant predictors). Make residual plots. Comment on the fit of this model. C. The regression model you fit in question 1b) seemed to fit well (i.e. the model with only boats). Is the model you fit in part 2b. better? What happened