Official AP Statistics Thread 2012

Test Preparation AP Mathematics & Computer Science
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<p>leehannah, that problem isn’t very difficult, you just have to punch a bunch of numbers into your calculator. You know you want an interval that contains 40% of the population (Battlebrick explained that), so use normalcdf(value 1,value 2,10,.2) for a-e to see which ones are around 40%. (I have a ti-84-plus silver, I don’t know if you can change the mean and std dev on other calculators. If you can’t, just convert to z-scores with the formula on the formula sheet). In this problem, you’re left with a,b and d. d is the shortes interval, so that’s the answer</p>

42

<p>Where can I find released exams?</p>

43

<p>Does anyone know how to calculate scores for this test? I got a 32/40 on a practice mc and was wondering what my average needed to be for the free responses.</p>

44

<p>I threw together a quick review packet for Chapters 18-27 of “Stats: Modeling the World”, but anyone could use it. It covers all the hypothesis testing stuff, chi-square tests, variance in regression, t-distributions, comparing distributions/means, probably some other stuff that I’m forgetting. Anyhow, it lives here: <a href=“https://docs.google.com/open?id=0B1qbMwu2Zub0ZmQ1YWhUS1pIYzQ[/url]”>https://docs.google.com/open?id=0B1qbMwu2Zub0ZmQ1YWhUS1pIYzQ&lt;/a&gt;&lt;/p&gt;

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<p>To figure out your score you can go to appass.com and put in how well you did and they calculate your score for you.</p>

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<p>I know it’s kind of late, but if you require any help on specific topics, there are excellent videos on YouTube under user #shpapstat. </p>

<p>Here’s an example video on hypothesis testing: [AP</a> Stat 11.1 - YouTube](<a href=“AP Stat 11.1 - YouTube”>AP Stat 11.1 - YouTube)</p>

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<p>Ah thanks! AP Stat seems pretty easy, I’m more worried about English language XD</p>

48

<p>Anyone want to host a chat for Stats Review?</p>

49

<p>and I can’t find any released exams except the 2002 one ><</p>

50

<p>I’ve pretty much given up on this test. Hated the class…I just hate mathematics in general. My school needs a 4 to count for credit which could get me out of the quantitative reasoning requirement, however there is another course that I want to take that would fulfill it. Really the only reason I’m taking it now is so that I won’t have to take my teacher’s exam…I think I did well on my other AP exams, so it’s whatev.</p>

<p>I’m not expecting to pass even though my teacher guarentees a 3…</p>

51

<p>may the curve be ever in your favor.</p>

52

<p>Hey guys, I have one question about the following problem.</p>

<p><a href=“http://i.imgur.com/vYbPi.png[/url]”>http://i.imgur.com/vYbPi.png&lt;/a&gt;&lt;/p&gt;

<p>The answer is D. I can get the first part (the expected total), but I do not know how to get the standard deviation.</p>

53

<p>ok i have no idea how to do this problem…help?</p>

<p>A psychologist theorizes there is a strong relationship between a person’s IQ score and their sense of humor. She randomly selected 45 adults and found the following results. IQ: Mean=105. Standard Deviation=12. Durante Test of Relevant Humor: Mean=140 Standard Deviation=24. r^2=0.81.
What is the predicted humor score if the IQ score of an individual is 110?
A. 51
B. 142
C. 148
D. 149
E. Cannot be determined since the individual data points are not known.</p>

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<p>I think it’s E</p>

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<p>@duuuuudley, to get the standard deviation, you have to add the variance of the two samples, then take the square root of that number. So, the variance of the first sample is 25(.1)(1-.1) (because st. deviation is the square root of n(p)(1-p)) and the variance of the second sample is 25(.45)(1-.45). When you add these two, then take the square root, you get 2.905</p>

56

<p>AP STATS EXAM IS NOT THREE-DAYS EXAM!! I haveen told that AP Stats exam is really easy, piece-of-cake exam which obcuring 5 is very possible if studying hardcore for three days. Former AP Stats students and exam-takers EMPHASIZED how easy the AP Stats is. Well, no! I have been studying Princeton Review for week and still cannot completely grasp the all information on Confidence Intervals. IDK why people call the AP Stats Exam as Three-Days Exam?!</p>

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<p>^ Maybe they’re math people? I’m def not!! I HATE this stuff!!!</p>

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<p>I’m not really worried about stats itself (you can get 24/40 and all 3s on FRQ and still get 5), but AP English is going to drain me of all my intellectual capacity!</p>

59

<p>Stats is not math… Stats is embodiment of the CollegeBoard and high school education’s emphasis on memorization over rigorous, intellectual thought. While even some AP history courses require minimal levels of analysis beyond the names, dates and events students are forced to memorize, one’s success in AP Stats is dependent solely in their ability to memorize equations for test statistics, conclusion statements and the processes to carry out tests. Seriously, a “curveball” on an AP Stats test will be little more than figuring out how the problem has been cleverly veiled to seem only tangentially related to the curriculum, but when in reality, a student just needs to be able to discern the slightly alien scenario. </p>

<p>/end rant</p>

<p>@SDFGXH: Answer is D. You have to construct a least-squares regression line with your given data (the equation is on the AP formula sheet). Do that whole plug-and-chug ordeal and you come out with an equation of: Predicted Humor = -49+1.8(IQ Level). From here, plug in 110 for X (or, in context, IQ Level) and you have your answer. </p>

<p>Just to add to my rant… a question like this is what I’m talking about. The content is primitive, you just need to be confident enough to discern what it’s asking.</p>

60

<p>Actually, stats is math…it’s logic, left-brained stuff obviously. What’s your definition of math? One must analyze and predict with data…using formulas, variables, etc…things that non-math people don’t like. People say it’s not math because it’s “mostly writing…” Yes, that part is true, but in order to write the analysis you need to logically figure out how to do the problem using memorized formulas and inferencing. There is nothing right-brained here that I can think of!! Even my English and History teachers hated stats.</p>

<p>Have you taken APUSH? The essays do not involve “just memorizing dates and events.” It’s all about analyzing the specific happenings. How can you write a 7 -9 paragraph essay only on memorized info? Lit and Spanish even more so.</p>

<p>Yes, I’m very biased against non-math subjects. :)</p>