<p>@febreze88</p>
<p>well the students were randomly assigned. a lottery had been given. i used this fact to satisfy the condition of SRS in part A</p>
<p>I basically did exactly what carlos did for a b and c. I don't remember what d asked.</p>
<p>I'm confident I got a 5 though.</p>
<p>For part D I talked about R-squared and how the regression line for the regular school explained much more of the variation in posttest scores than did the line for the magnet school. I'm not sure if this was something they were looking for but it was definitely something new learned from the regression analysis.</p>
<p>Can someone tell me what D asked? Because I do remember writing about the difference in the rsquareds.</p>
<p>What additional information do the regression analyses give you about student performance on the science
test at the two schools beyond the comparison of mean differences in part (a) ?</p>
<p>got the same stuff for 6 as carlos... for d i talked about the r-values... idk if tht is what they were looking for tho</p>
<p>carlos -</p>
<p>woops. see that's what i mean by "garbled." then its lucky i guess that i didn't write about any of that in my answer!</p>
<p>Just found this from earlier in the topic. I talked about the rsqaureds and then I wrote one sentence about how the slopes were different, meaning that for pretest scores lower than about 87, the magnet school did better.</p>
<p>How did you guys do 5 a and b?</p>
<p>I think I did a chi GOF test and then for b I just guessed at how to do it. I don't really know.</p>
<p>ok talked to my dad again & showed him the actual problem...</p>
<p>now he says he mostly agrees with what i remember from my answer (basically that the difference in scores at the magnet school was probably due primarily to the school itself, while the difference in scores at the original school was due primarily to students' original ability since posttest scores were correlated so strongly w/ pretest scores). he thought i could have said more though...but admits that he's not positive either exactly what the question was looking for.</p>
<p>llpitch: 5a was chi square GOF & 5b was just a matter of comparing expected # to observed # of moose (the answer was habitats 2 & 3 - esp 3)</p>
<p>^ I used chi square Independence for 5a...not GOF.</p>
<p>Why did you use Independence? Can you explain your reasoning, becaues I'm pretty sure I was correct in choosing GOF (+ febreze agrees =D)</p>
<p>I also did GOF
Because I think it was asking if the proportions matched.</p>
<p>For 6A, I also did the pooled proportions thingie that febreze [I think?] was talking about.
So my SD was: Squareroot of (p-hat)(1- p hat)(1/n1 + 1/n2)</p>
<p>I believe my final P value was something like 0.0117?
I'm fairly confident it was 0.01 something</p>
<p>I did independence b/c the "researchers" (as described in the problem) wanted to know if the number of moose in a certain habitat is proportional to the amount of acreage of that habitat. So in other words, is the number of moose in a habitat dependent on (or independent of) the amount of acreage of the habitat...</p>
<p>does anyone agree...or did I bomb this Q?</p>
<p>I did GOF too.</p>
<p>I don't think asking if the number of moose is proportional to the acreage
is the same thing as asking if habitat is dependent on acreage
Otherwise if it was independence they wouldve mentioned "dependent" somewhere, and not "proportional to".</p>
<p>I don't know.
I guess it just depends how you interpret it.
Our teacher gave us a fair share of homogeneity, GOF, and independence tests.
Usually the independence test mention dependence in the question.</p>
<p>
[quote]
For 6A, I also did the pooled proportions thingie that febreze [I think?] was talking about.
So my SD was: Squareroot of (p-hat)(1- p hat)(1/n1 + 1/n2)
[/quote]
^ do you mean 4c ?</p>
<p>you'llsee --> the use of the words "proportional" & "expectation" in the question led me to use GOF, which I'm fairly positive is right. since chi square tests are almost identical in terms of calculation, you may have come up with the same answer using independence, but i believe that the wording of the question indicates GOF.</p>
<p>EDIT: agreed w/ catalysis above.</p>
<p>For number 5
Did anyone get that there would be a 0.325 probability that Crystal scores more than Josephine?</p>
<p>I think so, catalysis. That was just adding up probabilities and figuring out what x values satsified the conditions, it was pretty easy.</p>
<p>Oh yeah 4c sorry.</p>
<p>For question 2 [ I don't remember what part, sorry] I said it was BETTER that they combined the results from the surveys because a larger sample size = less deviation = more chance they can make generalizations based on the population.</p>
<p>But I'm not sure.</p>