Answer Choices
50%
63%
70%
82%
Explanation for Question 18 From the Math (Calc) Section on the Official Sat Practice Test 8
So question 18 is a line of best fit question. 2 And just as a little definition, a line of best fit is the general 3 trends line that you put whenever you see a scatter plot. 4 So the line isn't perfectly connecting all the dots, 5 but it shows the general trend, the general direction in which the data points 6 move. And if we look at our question, 7 it says that we have a particular forest who is not shown in the 8 figure also called the graph, 9 right? So it's not another graph. And it has a mean annual temperature of 10 negative two degrees Celsius. So it shows up, 11 you know, about here in the negative negative two region. 12 And so it says based on the line as best fit, which is which 13 of the following is closest prediction to the set percent of leaf litter mass 14 remaining in the forest after decomposing for three years. 15 And so maybe the hardest part of this problem is that you see that 16 you're supposed to predict percent leaf litter, 17 mass remaining in the forest after three years. 18 And you look on your Y axis and all you see is leaf litter, 19 mass. So you might be thinking, what do I do with this three years 20 part? Where does this come in? And this is actually simpler than you would 21 think. If we read up in this beginning paragraph, 22 we see that the figure shows the percent leaf litter mass remaining after three 23 years. So when it says leaf litter, mass, 24 it is implied actually that is after three years, 25 right? So we don't have to do any math with the three. 26 All we had to do is find the negative to draw a line up 27 to where it is on the line of best fit and see that we're 28 at about 70. So our best answer is going to be C.