(ii) What percentage of the variation in the response is explained by regressing Onto the explanatonv variable? Do we have reaSon to believe in a linear relationship between these variables? State the formal hypothesis test (and the conclusions). (iii) What would the model predict for brain weight for a mammal with a bod},r weight of 35 kgs? If spredog 35) = 1.186 {in units of log grams), give a 95% predictive interval for the brain weight. The following questions pertain to a regression model fit, summarized below, to data on the brain weight (brainwet, in grams) and thebody weight (bodywet, in kilograms) of 62 mammals. Call : Im (formula = log(brainwet) ~ log(bodywgt), data = mammals) Residuals : Min 1Q Median 3Q Max -1. 75335 -0.53911 -0. 09239 0.42068 2.61153 Coefficients : Estimate Std. Error t value Pr(>|t/) (Intercept) 2. 18328 0. 10682 20 . 44