<p>for 3c, i forgot what i did but i got like 66 households, and im pretty sure that’s the right answer because i plugged it back in</p>
<p>when are the scoring guidelines released??? I really really want to know what I missed on the FRQ. I am pretty sure I missed <em>A CERTAIN PROBLEM</em> (can i say which?) because I looked it over again when it was released today and realized i did it wrong… -_-
I really really wanted a 5 on this. I studied so much…</p>
<p>Here is 3 c:</p>
<p>use the margin of error formula given the 95% confidence interval, 0.417 +/- 0.119:
ME = c.v. * se(est)
ME = z<em>(95%) * sq.root (P’Q’/n)
0.119=1.96</em>sq.root( (0.417<em>(1-0.417))/(n))
0.119^2=1.96^2</em>(0.417*(1-0.417))/n
n= ((1.96^2)(0.417)(1-0.417)) / (0.119^2)
n= 65.95 ~66 households.</p>
<p>I divided by root n twice</p>
<p>Oh man, I somehow managed to forget z* in my equation :(</p>
<p>I remember writing it out, but I guess I forgot to type it in my calculator
Stupid mistake D:</p>
<p>“for 6 e did you guys reject the null hypothesis?”</p>
<p>If i remember correctly the null was that all areas were effected equally by hurricanes, so yes I did reject the null. I got 6.4 for Q and I think that matched up to a p value around 1.8 or so, so i rejected it.</p>
<p>Q=6.4. From the frequency plot you would observe that ~39/1000 [or 23/1000, but it’s not clear whether the bar at ~6.4 is 6.4 or 6.3, but you get the logic and you would still reject the null!] values are 6.4 or higher. Our p-value of 3.9%[or 2.3%] indicates that we would get a result as extreme as that observed ~3.9% of the time. Since p-value is 3.9%[or 2.3%!]<alpha=5% we would find the results statistically significant. We would reject H0 [H0: there is no significant difference in the distributions of hurricane damage amounts among the three coastal regions.] and conclude that there is evidence that there is a significant difference in the distributions of hurricane damage amounts among the three coastal regions.</p>
<p>I freaking messed up on 6. I somehow got 5.2 and then i checked and I got 6.4. Stupid calculation error. </p>
<p>I pray for a 5.</p>
<p>Is anyone else surprised at the relative simplicity of Question 6? Our teacher told us multiple times how Q6 is usually extremely difficult and incorporates some stuff we haven’t dealt with before. Her advice was to “do the best you can”. However, I didn’t think any part was confusing or totally out of the norm. Here’s hoping for a 4 on Q6!</p>
<p>for number 3 , about the 40 songs, how do you fing the mean and sd of 40 song</p>
<p>@tcherry2011</p>
<p>let x be a random variable denoting lengths of rock-n-roll songs in minutes
We are given that the mean is 3.9 minutes and the st. dev is 1.1 minutes</p>
<p>E(x-bar) = mu = 3.9 minutes
St. dev(x-bar) = Sx/sq.root(n) = 1.1/sq.root(40) = .1739</p>
<p>how many points would i get if i got 68 instead of 66 for #3c cuz i used .5 instead of .417?</p>
<p>for #6 the median is considred an average too isnt it and for this problem it seemed more appropriate…</p>
<p>^uhh no…‘average’=‘mean’, not ‘median’.</p>
<p>No, average doesn’t necessarily signify the mean. </p>
<p>@cresselia
I have to agree that the median would seem more appropriate; as long as you indicated what you were doing, I think you should get full points.</p>
<p>@redfirex67: yes the same exact thing happened in my class. my teacher spent a lot of time emphasizing how you should attempt 6 even if it’s harder and they throw tricky stuff at you but it’s worth more points…and then 6 ended up pretty simple. 
I was happy.</p>
<p>Can we compile an organized list of solutions for the FRQs on this exam? I went through this thread and there are bits and pieces of answers but nobody has definite answers for complete problems. Surely somebody has solved these by now. I found a site where somebody had solved the FRQs for Calc and listed them. Maybe the solutions for the AP Statistics exam are posted online somewhere, but I can’t find them… Any input guys? It would be much appreciated. :)</p>
<p>Does anyone who took the test this year have any advice? Esp regarding review books? I’m self-studying it next year. Sorry, not attempting to thread hijack just thought Id go straight to the source :)</p>
<p>^Get REA and study it like crazy. It is the AP Statistics bible. Most people will tell you to use Barron’s but IMO, you would be best off using REA. It’s a lifesaver. Now, back to the matter at hand. Does anyone have the solutions to this?</p>
<p>What’s the name of the nonparametric test with the Q statistic in the free response question about hurricanes?</p>