Explanation for Question 11 From the Math (Calc) Section on the 2019 March Sat
So question 11 asks according to the model, 2 which of the following is closest to the expected age, 3 to the nearest whole year of a Flathead catfish that is 31 inches long. 4 So we know that in this case, the Y value is the length. 5 And the T value is the years after the first year of life. 6 So all you have to do is take this equation here and set this 7 equal to 31 because the Y value is simply the length. 8 So let's do that. Now, 31, which is the length of the catfish is 9 equal to three T plus four, 10 and then we just have to solve backwards. So first subtract four from both 11 sides that gives us 27 is equal to three T and 12 then divide by three. Can we get nine is equal to T. 13 Now the answer isn't nine because T represents the years after the first 14 year of life. So that means that we have to take whatever answer we 15 got and add one to it. And so nine plus one equals 10, 16 and the answer is a 10 year.