Explanation for Question 30 From the Math (Calc) Section on the Official Sat Practice Test 6
Section 30 or question 30 gives us this scatterplot and it asks us the 2 scatter plot below shows the amount of electrical energy generated and millions of megawatt 3 hours by nuclear sources over a 10 year period. 4 So on the X axis, we have time. 5 So as it increases from left to right, 6 we have time increasing. And then on the Y axis, 7 we have energy in million megawatt hours, 8 and then it's titled electric energy generated by nuclear sources. 9 The question reads of the following equations, 10 w which best models the data in the scatter plot. 11 Okay. So this might be pretty intimidating at first. 12 This is a lot of really complex numbers, 13 and I'm going to let you in on kind of a hint. 14 There's no way that you'd be able to drive these equations yourself. 15 You have to look at the graph and tell which one is going to 16 fit based on some key characteristics. 17 So first it's asking which best models the data. 18 So we're finding a line of best fit and to find a line of 19 best fit. We draw the approximate line that passes through as many of these 20 points as possible. And we can see from our answer choices that it's going 21 to be a quadratic, which hopefully you remember looks roughly like 22 this or like this, 23 or any variation of the, so it kind of looks like a U shape. 24 So drawing through received the line of best fit is going to approximately look 25 like this. And that's a really, really lovely rough line, 26 but we can tell some very important feature...