need help with probability stuff NSFW Lemon Party link

[gabe]

i have a bunch of work due in my probability class due tomorrow. i havent been to class all week. also, ive never had a probability class before.

the assignment is mostly related to the normal distribution. the first question is something like: 'flip a coin 400 times, if H is the number of heads, find the normal approximation to P(190 < H < 200)'

help me get started.

[cobere]

You would think, asking a bunch of poker players, that you'd be inundated with replies. Its been way too long since my Discrete Math class where i did this stuff.

[bigred]

Still got that add drop form?

[gabe]

aww cmon guys

[thenonsequitur]

Does this help?

http://onlinestatbook.com/chapter6/normal_approx.html


{NSFW - Xianti}

[Pelion]

i have a bunch of work due in my probability class due tomorrow. i havent been to class all week. also, ive never had a probability class before.

the assignment is mostly related to the normal distribution. the first question is something like: 'flip a coin 400 times, if H is the number of heads, find the normal approximation to P(190 < H < 200)'

help me get started.

Ok. I dont know what a normal approximation means, and its been a long time since ive done this but id do this ===>


First you gotta standardise the thing. You give each of your numbers a Z score.

Z score is the number of standard deviations from the mean your number is.

Tossing a coin 400 times you expect the mean number of heads to be 200 so from each value you take 200.

you now have

between -10 and 0.

Now you divide by the standard deviation.

The standard deviation in a binomial problem is given by

sqrt(N*p*(1-p))

where N is the number of trials
p is the probability of a success (50%)

so in this case the varience (standard deviation squared) is

N*p*(1-p) = 400*0.5*0.5 = 100

so the standard deviation is 10

so your standardised results should be between

-1 and 0 standard deviations of the mean.


Somewhere or other you should have a table that tells you the percentage of area of a normal distribution curve that lies between 0 and z.
If not then this one will do (http://www.statsoft.com/textbook/sttable.html).

It says that 0.0398 of the area lies between 0 and 1 (or 0 and -1). In other words the probability P(190 < H < 200) = 0.0398.


As I said before its been a while since ive done this so if it turns out to be bollocks then...well.... meh.
I think its right though. If you need anymore explaining ill be awake a little while yet.
Goodluck

[Pelion]

Does this help?

http://onlinestatbook.com/chapter6/normal_approx.html

you are my hero.

[Miffed22001]

i never found this question on my english finals.

[gabe]

pelion, thanks. i owe you a favor, let me know when you need one.

[a500lbgorilla]

going to class is both annoying and terrible!

[Irisheyes]

Push the flop.

[Irisheyes]

Push the flop.

Hahah funny one Irish.

[arkana]

Does this help?

http://onlinestatbook.com/chapter6/normal_approx.html

Although i find this pretty hilarious, some of us are at work and can get into serious trouble clicking on a link like that.

[Pelion]

Does this help?

http://onlinestatbook.com/chapter6/normal_approx.html

Although i find this pretty hilarious, some of us are at work and can get into serious trouble clicking on a link like that.

Good point I forgot about that. This thread needs a Giant NSFW lable

[thenonsequitur]

I'd like to apologize for my post. I didn't mean to get anyone in trouble, and I hope I didn't.

I know how much employers hate seeing their employees studying probability theory when they should be working.

[givememyleg]

I know how much employers hate seeing their employees studying probability theory when they should be working.

Yeah that's why I was fired from my last job.

[bode]

Does this help?

http://onlinestatbook.com/chapter6/normal_approx.html

so im at work, and we were talking about probabilities earlier in the day. i see this thread and read gabes question and pelions response, so i decide to look at this link to see what this was all about. obv. to my surprise, this has nothing to do with probabililty, but more with geriatrics smoking pole. while i found this trickery very funny, my boss, who happened to be walking behind my desk, found it quite offensive.

for the short story, he calls me into his office and tells me to explain myself. so i did. truthfully. he found this very hard to beleive, and quite honestly, i cant blame him. he gives me the preverbial tongue lashing, and i go about my work. then about 5 minutes ago, he calls me in again, and tells me he "doesnt require my services anymore."

So i just want to say, a big FUCK YOU for posting this and getting me fired.

and yes, i would like to strangle you.

[a500lbgorilla]

trying to figure out if Bode-ist is lying.

[thenonsequitur]

I think it's a dramatization to prove I point. I get it, and I'll be more careful in the future.

[Renton]

Does this help?

http://onlinestatbook.com/chapter6/normal_approx.html

owned

[Warpe]

for the short story, he calls me into his office and tells me to explain myself. so i did. truthfully. he found this very hard to believe, and quite honestly, i cant blame him. he licks his lips with his tongue and winks at me, and i go about my work. then about 5 minutes ago, he calls me in again, and tells me he'd "like me to stay late to provide him with some special...um...services."

So i just want to say, a big THANK YOU for posting this and getting me a raise.

fyp

[bode]

ok, obviously im not that great of a liar, or story teller for that matter. Lukie, maybe some lessons please.

bad attempt at fucking with you guys. ill try harder next time.

and btw, nice FYP warpe, it made me el oh el

[Lukie]

ok, obviously im not that great of a liar, or story teller for that matter. Lukie, maybe some lessons please.

bad attempt at fucking with you guys. ill try harder next time.

and btw, nice FYP warpe, it made me el oh el

I charge $1,000 an hour for storytelling lessons, dude. However, things are in high demand now so you better get in quick before I have to raise my rates!

By the way, the more relevant question for gabe is this:

How much expectation have you passed up trying to figure all this goofy shit out?

[gabe]

probably 2kish

[Galapogos]

I didn't know Pelion was that smart. Not a knock at him or anything. Just didn't strike me as a university guy for some reason.. it's hard to make this point without it sounding like I'm making fun of the guy. This is one of those posts I should bother completing yet watch as I submit it anyway...

[euphoricism]

It should be well assumed that reading ANY post in the community forum while at work/school is a very, very bad idea.

[bigred]

It should be well assumed that reading ANY post in the community forum is a very, very bad idea.

FYP