AP Statistics. OH BOY 8D

[Suna-chan]

Well, here's a class that really shouldn't be too hard. I know that I am not completely lacking in the division of math (I've been in accelerated courses and have maintained A's and B's), but I feel really frustrated with this class.

The teacher was brought in during the middle of the year last year, when the old stats teacher was in a car accident and broke nearly every bone in his body o-o (needless to say he wasn't up for teaching after that...). I know that several students had MANY problems with this teacher last year, which is somewhat understandable.

Now, she's a nice person... and she really knows a lot about what she's doing. Only problem is that she is TERRIBLE at communicating how to effectively work a problem. I've had very similar problems in the past, as I know many of you have had.

Anywayyyy I think I'm going to turn this into more of a rant now. KAY.

Yes so the teacher has been putting us either into groups that she assigned (groups of 2 to 3 people) OR telling us to work INDEPENDENTLY and SILENTLY on our work.

I have a big problem with both of these because 1) what if your group as a whole doesn't understand how to do something? She doesn't let us confer with other groups...she yells at us to "Stay in your own groups! Don't talk outside of your group!" ... and I understand that she wants us to try to work through something, which I can usually do, but I need that extra jump-start sometimes....and this method of isolating us from the rest of the class... just ain' workin' for me. Especially when she says to work independently. She won't even allow us to ask one or two questions to our neighbors. :/ Which, for me, means... sitting and staring at a problem for 30 minutes and still not understanding it.. where if I could only ask a brief question, then I would more-than-likely understand what to do.

-sigh-

Also, she keeps calling me out. Calling me out, saying that I talk too much, and that she's going to have to seperate me and Inaam (my friend and person I sit next to) because we are "disruptive." NOW. My biiiiiiig problem here is that there are TONS of other people talking in class.. people MUCH louder than Inaam and I are, and I've even asked people in class if they think that we (Inaam and I) are disruptive or even loud. Every single person I asked said that they've never even heard us talk in class.. :\ mmwtf.

I think it's just because we sit in the back corner and I'm kind of wiggly... haha, well I am. In math class anyway. I move around a lot in my chair and stuff... but no one ever seems to notice - except the teacher.

ANYWAY yeah there's my big ol' rant about AP Stats. I have a test tomorrow over material I don't understand because we've spent the last two weeks working independently or in groups... OR doing pointless activities that don't help anyone YAY 8D

Well, if you've read through this much and have anything to say, please say it! Any advice/comments is very welcome :)




PS: Anyone know how to work this problem?



The rate of return on stock indexes (which combine many individual stocks) is approximately normal. Since 1945, the Standard & Poor's 500 index has had a mean yearly return on 11.8%, with a standard deviation of 16.6%. Take this normal distribution to be the distribution of yearly returns over a long period.

A) In what range do the middle 95% of all yearly returns lie?
B) The market is down for the year if the return on the index is less than zero. In what percent of years is the market down?
C) In what percent of years does the index gain 25% or more?


(I tried to use the 68-95-99.7 rule...but you end up with negative percentages...and i just wasn't sure what was up :p) any explination would be super handy :D

[Blackmage]

I'm sure Ber does... I never took stats now that I think about it... Oh well all of my math classes are done and over with for school

[Chixiethepixie]

ive got a teacher who doesnt explain what she is teaching us so the whole class is sat there with vacant expressions on our faces but when we ask a question she looks at us as though we are thick and it really pee's me off so i know how frustrated you must be-i feel like asking her if she deliberatly wants us to fail the course.

[Shammy]

"The rate of return on stock indexes (which combine many individual stocks) is approximately normal. Since 1945, the Standard & Poor's 500 index has had a mean yearly return on 11.8%, with a standard deviation of 16.6%. Take this normal distribution to be the distribution of yearly returns over a long period.

A) In what range do the middle 95% of all yearly returns lie?
B) The market is down for the year if the return on the index is less than zero. In what percent of years is the market down?
C) In what percent of years does the index gain 25% or more?


(I tried to use the 68-95-99.7 rule...but you end up with negative percentages...and i just wasn't sure what was up :p) any explination would be super handy "

A) You said you looked at the 95 rule. That's two standard deviations on either side. Which means while 11.8% - 16.6(2) is negative... i think it's 11.8-33.2= -21.4% at the same time, 11.8+33.2 gives you +45%.

Since you are working with returns on the stock market, I believe part of the range being negative is alright. Afterall, it's possible to lose money when you invest, isn't it?

B) This is tougher for me to do since I don't have my notes from last year and I dont remember exactly how it works. However, if you can figure out how many standard deviations 0 is from 11.8, can't you figure out what the probability is of the return?

C) You would check for the probability when you have a med of 11.8, std of 16.6, min of 25 and max of infinity, i think. something along those lines. i remember using my TI-86 (i think it was an 86...) last year, plugging in MED STD MIN and MAX and getting a probability. this might also be the way you work B.

In any case, I hope some of this is helpful. I didn't retain a ton of information, I'd probably have it right back if I just looked at the notes I had, but I can't find them.