<p>The answer was z=0, not y=0 and x=0</p>
<p>It was z=0. </p>
<p>And the volume question…the answer was 4 i believe.</p>
<p>I omitted the conical question and the one with (√21,2)</p>
<p>the lowest on the volume question was 8.31</p>
<p>The height was like 14.something. You needed to take the ratio of the old radius to new, and use 1/2 volume to solve for what the new height would be.</p>
<p>for the stats question did standard deviation also get higher or did it stay the same?</p>
<p>I said it got higher</p>
<p>was the conic one (-2,5)?</p>
<p>I said the standard deviation would also go higher. </p>
<p>What about the other standard deviation questions? The mean was 76, SD=2…where is 84?</p>
<p>I forget exactly what it asked. If it was asking “which ones would definitely increase?” the answer did not include standard deviation, because with the following data:</p>
<p>10
80
80
80
80
80
80
80
80</p>
<p>mean = 72.2, SD = somewhere in the 20s</p>
<p>you can remove the lowest and add a 94 and the new SD is like 4.</p>
<p>I’m pretty sure the deviation change. Originally it was all 78, but then you had all 78s until the last one, which was like 95.
I wasn’t sure about the one with the bell curve though</p>
<p>thats the one I got wrong, because I did at the very last moment. :(</p>
<p>84 was in the 50-80ish percentiles</p>
<p>Unless I misread, it only said that the mean was 78.</p>
<p>It was not possible to tell whether the standard deviation would go higher. Just because the mean was like 77ish and the new score is a 95 when the lowest score was dropped, the dropped score could be like a 26 or something ridiculous which means the standard deviation does not automatically go higher.</p>
<p>I said 84 was over 99th percentile, I mean think of it, with a mean of 74 std. dev of 2, 84 is a whopping 5 std. dev’s above the mean, which is way over 99th percentile</p>
<p>ap stat student here: the standard deviation can POSSIBLY change but it asked what must change…so mean was the only answer… and the one with the bell curve you had to do 84-74/2 and you get 5…then u put in you calc normcdf(5,infiniti) and there is ur above 99th percentile</p>
<p>Yes, 84 was definitely over 99th percentile. it’s like 99.9997th percentile.</p>
<p>^^ Agreed. Look up the empirical rule, that justifies it</p>
<p>it was z=0 im so dumb what was the cone one</p>
<p>oh really? it’s only mean?
thanks, that saves me one. that means i missed so far that i know of; 2.
oh how i hate my mistakes…</p>