***November 2013 - Mathematics Level 2***

<p>Do you guys remember any vectors?</p>

<p>Wait but if shes 80th percentile out of 40 people wouldn’t that just make her 8/40 so shes in between?</p>

<p>no it wouldnt @omgifailed bc the percentiles are based on standard distribution which we dont know and since we dont know it nor the mean we dont know where 80th percentile is.</p>

<p>@omgifailed lol your username i feel the same</p>

<p>@kerning i dont remember any vectors
@thecreator96 a = b they both equal 2.</p>

<p>Hmm how’d it compare to barron’s? What else is there?</p>

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<p>Well if you consider percentile in terms of marks or in terms of rank, and that none of the three had the same percentiles, we can easily conclude that it was in between.</p>

<p>That question with the .6 probablility of one thing and .4 of the other and what’s the probability of at least one shipment…
I said it was .76 </p>

<p>because 1 - probability you get none
and probability you get none is .4 x .6
therefore the answer is .76 ya?</p>

<p>@noooooo that’s what I got .24+.36+.16</p>

<p>ALso For the question that had the population start at 16.1 million grow at a rate of .3 percent for 25 years, was it 7.5?</p>

<p>no @hippiej512 it was like the 7.78 at least that’s what i got</p>

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<p>No I think percentile of an element depends on the position of the element in an ordered list. </p>

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Wikipedia</p>

<p>We use methods to find out the value corresponding to a percentile but not the percentile.</p>

<p>^ I chose in between on the test. But if 80 percentile can be anything higher than 80%, does that mean the answer is “not enough info”?</p>

<p>I thought that 80th percentile meant that she did better than 80% of the people who took the test… So she was in the top 20%, so she was in the top 8… but that doesn’t necessarily meant that she did worse than Pablo, because there could have been like 2-3 people who shared any of the top 4 scores in the class. If 8 people or more earned one of the top 4 scores in the class, then she did better than Pablo, so the answer would be “need more info.”</p>

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<p>No it only means that a 80% of all the others scored below. (has lesser values).</p>

<p>So if a John scored 32 in a test and that was the 80th percentile (he’s better than 80% of the test takers) then anyone who falls on a lesser percentile has scored less than him. </p>

<p>Percentile is different to percentage which is just scaling it from 1-100. Percentile scaled the scale into a hundred parts where the value of each nth percentile is such that n% of the people or elements has values that are lesser.</p>

<p>The answer was in between:</p>

<p>There were 40 test-takers.</p>

<p>80% percentiles means you above 40*.8=32 of the test takers.</p>

<p>This makes her below 5th, but higher than 34th.</p>

<p>For the exponential question, it’s 100%</p>

<p>16*(1.03)^x is the equation. 1.03^25 is about 2, meaning the population doubled, or grew 200%</p>

<p>the growth was .3 percent, so 1.003^25, so its increased 7.78%</p>

<p>It was in between. Sgtgutter is correct.</p>

<p>What was the one with the number like 4,ABC,239,040 and it asked for the sum of a b and c? What was the standard deviation one with the boxes, I guessed and put 2.1 but now I think about it Im guessing it was .1? What did you guys get for the largest angle of the triangle with sides 15 40 and 52, I put 87 but I think its 137.</p>

<p>for the 4,ABC,239,040 it said multiples of 3. so the only possible option is 3 6 9. 3<em>6</em>9=162 so A + B + C = 0. The largest angle was 137 i think its just law of cosines opposite 52.</p>

<p>@danielfelsen the answer for 4,ABC,293,040 was because they said the 6 consecutive numbers of multiples of 3 get you the value 4,ABC,293,040. then you had to find the sum of ABC which i believe was 5. Do 33x36x39x42x45x48 and you see it</p>

<p>@noooooo the probability question ask for the probability of one or the other so you had the subtract the possibility of get both then the possibility of getting neither from 1.</p>

<p>@nooooo was one of the answer choices .52 for that probability question.</p>