AP Statistics Discussion

<p>i didnt..because i remembered something like np and sqrt npq and stuff
so i just wrote the conditions such as sampel size large enough..blah</p>

<p>I did matched pairs! woot!</p>

<p>you dont have to know the population standard deviation for 2 sample proportions, you use Pc</p>

<p>I asked my Stats Teacher about 4. It is indeed a matched pairs test (according to him).</p>

<p>It's matched pairs, because if you do the two-sample t-test, you'll also deal with the variation of the amount of e. coli in the different specimens of beef.</p>

<p>what was:
1a
3c
5a</p>

<h1>6 (besides part a and maybe b) was bull. we never learned how to do hypothesis testing on regression lines... it was chapter 14 which my teacher didn't cover because we were short on time and he said it usually isn't on the test.</h1>

<p>hey, does anyone know the raw score necessary to get a 5.</p>

<p>so i know this sounds quite stupid but on the paper, i wrote matched pair t test and even put assumptions for match pair t test, but i used the 2 samp t test program on the calculator. well that was stupid</p>

<p>"Two different methods of determining the level of contamination were used on each of ten randomly selected specimens of a certain type of beef."</p>

<p>Therefore, there was only one sample which was tested with two different methods and a matched pairs test is appropriate.</p>

<p>mjlaxstar, a raw score of 68 is needed for a five.</p>

<p>edit: yeah, my class didn't go over Ch. 14 either. I just tried to use t-tests for different values of the x variable to try to demonstrate a significant difference between actual and perceived distance, but that obviously wasn't what they were looking for.
did my best though, considering.</p>

<p>wait but i mean the conclusion was the same right? you reject the null?</p>

<p>On the ones where you had to state conditions, if you had everything right but didn't have any of the conditions, what score would you get?</p>

<p>I think I had some of the conditions, but I'm not sure how many were right, so I'm just going with worst-case scenario of 0 conditions.</p>

<p>reject Ho is right.. p was like 0.003 i think</p>

<p>3) c. It is ok to use the normal distribution because of the power of large number. If the sample size is large enough, regardless of the population distribution, the sampling distribution will have an approx. normal distribution. And according to the Central Limit Theorem, for mean, the sample size is greater or equal to 30 and this sample size in b meets this requirement.
4) a. I think they want us to use the 2-sample t test because they want to compare the two means of two methods " a significant in a mean amount." not that they ask for the difference in method A and B.
5) a. it is an experiment because the treatment was assigned randomly to the subjects by the researchers.
6) c. The null hypothesis is B=1
The alternative hypothesis is B greater than 1.
Yes we reject the null .</p>

<ol>
<li><p>i think the general consesus is that it was matched pairs. both tests are meant to test for differences, the only thing that separates them is whether or not there are untested variables that matching can eliminate. in this case it was the variation in bacteria levels for each specimen of beef</p></li>
<li><p>reject the null of B=1? im pretty sure it was fail to reject. slope was 1.102, SE was .393,</p></li>
</ol>

<p>sorry the test statistic is .25954 How can you find the P-value at df=38 in the chart?
For sure its over .25 ... so I guess fail to reject. Now I dont remember what I put :)
Is this the only test you fail to reject in the whole exam? Is there anyother? b/c I remember I put fail to reject in one question</p>

<p>just go to the next lowest df on the chart, 30. you may have failed to reject 5d, it could have gone either way, just depends on your explanation.</p>

<p>number 4 was definitly matched-pairs. each piece of meat was subject to all treatments. that is the definition of a matched-pair set-up.</p>

<p>WHAT DID YOU GUYS PUT FOR 1a?</p>

<p>That one boggled my mind. I essentially put the definition of Standard Deviation.</p>