The Official December 2012 Sat Subject Test Math Level 2 Thread

Test Preparation SAT Subject Test Preparation
41

<p>Okay so the question was something like: if x^2-y^2=1, and -1<(x-y)<0, what is true about (x+y), right? At least that’s what I remember it to be like…</p>

<p>So what you had to do was:

  1. split up the difference of squares (x+y)(x-y)=1
  2. plug in any negative fraction (whose value is less than -1) as (x+y)…
    I used -1/2, so I had (x+y)(-0.5)=1
  3. Looking at it, it was easy to observe that (x+y) had to equal -2… </p>

<p>So, in order for the equation to be true, (x+y) had to be less than -1, which was answer A I believe.</p>

42

<p>What was the answer to interquartile range question?</p>

43

<p>The interquartile range was 50%. Interquartile range means middle 50%- 25th percentile to 75th percentile. Like when a college gives their middle 50% for test scores? That’s the interquartile range. That and the standard deviation question were blessings to any AP Stat student.</p>

<p>I got that it was the January of every odd-numbered year after 1990. Just plugged into my calculator, found the max.</p>

<p>edit: looking at other thread, apparently, the IQR question was 31%? wut. Oops. Damn you stat.</p>

44

<p>The answer to the standard deviation one was the graph where everyone got the same test score, right?</p>

45

<p>Yes. Standard deviation of 0 means everything value in the set is equivalent.</p>

46

<p>The standard deviation question wasn’t 50%. The question was asking what percentage the range was of the standard deviation. I believe it was 30 something percent (I don’t remember the exact number).</p>

47

<p>did anyone get number 17 (sounds dumb) but you had to find the distance and they gave you the cube with an edge of 10. The answer wasn’t above 30 but i was deciding between the 21.22 something like that and 24.23 something like that or 20. I was down to those 3 and guessed. does anyone remember?</p>

48

<p>Yeh i think 24.14 or something? 10 + 7.07 + 7.07 from 5^2 + 5^2 = 50, and square root of 50 is 7.07, using Pythagorean theorem. So 24.14. </p>

<p>Sorry bad response/lack of clarity, don’t have much time. Hopefully that helps, though.</p>

49

<p>Yeh i got 37% but then didnt see that in the answers so chose the closest one, 31%, which I think was right.</p>

50

<p>@haginrainbow I got 31 as well. Also, do you remember whhat letter choice the 24.14 was??</p>

51

<p>So what did u guys get?</p>

52

<p>OMG I got a 660, I’m thinking of making a request to verify my scores… That totally took me by surprise, I just can’t believe I did so bad…</p>