Chem 3a help!!!!!!

<p>So i just miserably failed my second midterm, i got a b on the fist one, the average was 120/150 std of 25, the avg. for this one was 82 std. of 28. i don't know what to do! i have to get at least a b- is it possible? can i still study my ass off for the final and pass with a decent grade?</p>

<p>what did you get on the second one? how are you studying for the class?</p>

<p>im in the same class :) got 142/150 this midterm :) but anyways</p>

<p>since the grade is based on three tests equally</p>

<p>this is how you do it mathematically:</p>

<p>(grade you want)= (1/3)(percentage of what you got on the first midterm) + (1/3)(percentage of what you got on the 2nd midterm) + (1/3) (x)</p>

you want to know how well you need to do in the last test to get an overall of 85 percent:
you got an 80 percent on the 1st test, you got a 62 percent on 2nd test</p>

<p>85=(1/3)(80) + (1/3) (62) + (1/3)(x)
do some algebra. solve for x.
if x is more than a 100, then it might be impossible to get the grade you specify.</p>

<p>you have to remember that only 5-10 percent in pedersen's class is going to fail</p>

<p>the distribution of grades is as follows:
A (15-20%); B (35%); C (40%)</p>

<p>his curve is generous :) so dont loose hope!</p>

<p>thanks and congrats! that's really good. yup i just need to stay on top of this and do really really good on the final. do you do study groups? maybe you can help me out haha</p>


<p>Ok, person here who has ACTUALLY TAKEN STATISTICS.</p>

<p>You can calculate (roughly) what percentile you fall into by adding the means and then square-rooting the sum of the squared standard deviations, then seeing how many standard deviations you are from the combined mean. Then look in a table of standard deviations (available online) and you'll find out approximately where you fall.</p>

<p>...I want to do this for my own stuff since I didn't go to class the day after the first midterm, so the combined stats are:
Mean: 202
StDev: 37.5</p>

<p>His curve is only generous on the B range, by the way - the A-range is perfectly normal (generally taken that one standard deviation above the norm equates to an A in a curved class, at least to my knowledge...and 1 standard deviation above the normal equals approximately the top 15% unless the distribution is fairly heavily skewed).</p>

<h2>Also, the rubric is a tad misleading on the fails - he specified in the first day of class that he had no intention of failing anyone who didn't do poorly enough to deserve it.</h2>

<p>Also, the fact that the stats for this most recent midterm are so dreary is a pretty damn strong cue that calculating a regular percent is hardly the best approach to determining your grade.</p>

<p>study groups don't really help for orgo. do you go to office hours? that probably would help more.</p>

<p>Okay all you need to do is spend a lot of time alone with his problem set books. Start with the problem sets, you probably won't get anything right for a while, but just look at the answers and then try to redo it and figure it out. I usually struggle with the problem set until about halfway through and then I start getting things right. </p>

<p>Pedersen's tests are actually really predictable if you've gone through the problem sets. I learned this towards the end of 3A and then aced like every test in 3B by just spending the 2-3 days before figuring out the problem set books.</p>

<p>great. that probably means i'll fail chem 3a in a year. im SO glad I chose berkeley (or college in general). lol</p>

<p>@DN: it's not too bad if you keep up with the material, really.</p>

<p>a good tip i have is to flashcard reactions. while it's "good" to know all the mechanisms for the reactions that you study, it's far more useful to memorize reactions for the sake of doing well on tests. you study so many reactions in the chem 3 series that you won't be tested on the mechanisms of all of them, just the important ones. </p>

<p>i realized this shortly before my chem 3b final, but by that time it was too late. i had already written all the mechanisms out and knew them by heart, haha.</p>

<p>That seems like it'd be more an artifact of 3B with far I haven't seen a single mechanism I could have predicted straight up on any of them. I knew roughly what each one would look like going in, but that's because I know what the different reaction types look like.</p>

<p>...which may be what you're driving at. I don't know. >.></p>

<p>yeah that's the point i was trying to make lol.</p>