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whos good w/ conditional probability?

Posted: Wed Mar 04, 2009 1:55 am
by user
120 people: 95 bots, 108 plvls and 10 neither.

a. random person selected, what the probability the person either bots or plvls? 0.9167
b. the person doesn't plvls, what is the probability he bot? 0.4000
c. are botting and plvl independent events? no

quote to review answers

1. 10 people don't bot or plvl, so if you minus those legits from the pool of people, you'll get people who either bots or plvls

Re: whos good w/ conditional probability?

Posted: Wed Mar 04, 2009 2:27 am
by ImmortalKiller
user wrote:120 people: 95 bots, 108 plvls and 10 neither.

a. random person selected, what the probability the person either bots or plvls?
b. the person doesn't plvls, what is the probability he bot?
c. are botting and plvl independent events?


You are bad at explaining this, but I'll have a go.
I assume that you mean to imply:
Of the 95 bots and the 108 plvls, only 15 of the bots aren't PLVL'ing, and also, only 2 of the plvls aren't botting. And 93 people both bot and plvl.

BUT, I remind you, you aren't good at explaining this. If I've misinterpreted, please, work on conveying your message in a more understandable manner. Use that venn-diagram thingy. It helps.

A) 11/12.
B) 1/6.
C)
The two events are independent IF:
P(Bots)*P(PLVL) =? P(Bots and PLVL)
95/120 * 108/120 =? 93/120
.7125 =/= .775
No, the events aren't independent.

Re: whos good w/ conditional probability?

Posted: Wed Mar 04, 2009 3:01 am
by magisuns
gd out of otl... now

oh wait equation thingy >_>

Re: whos good w/ conditional probability?

Posted: Wed Mar 04, 2009 3:02 am
by Jstar1
I took AP statistics last year and pretty much forgot everything so can't do any of those

Re: whos good w/ conditional probability?

Posted: Wed Mar 04, 2009 3:17 am
by user
ImmortalKiller wrote:
user wrote:120 people: 95 bots, 108 plvls and 10 neither.

a. random person selected, what the probability the person either bots or plvls?
b. the person doesn't plvls, what is the probability he bot?
c. are botting and plvl independent events?


You are bad at explaining this, but I'll have a go.
I assume that you mean to imply:
Of the 95 bots and the 108 plvls, only 15 of the bots aren't PLVL'ing

no? there are 10 people who doesn't bot or plvl

Posted: Wed Mar 04, 2009 3:18 am
by DarkJackal
Wouldn't A be 9/10, if 108 either bot or powerlvl out 120, that's reduced to 9/10?

and B. 1/60? If there's only 120 ppl, get rid of the powerlvlers = 120-108 = 12, 10 of which do not, your left with 2 that bot but don't powerlvl, 2 out of 120 = 1/60?

Re: whos good w/ conditional probability?

Posted: Wed Mar 04, 2009 3:20 am
by user
where did you get 9/10 from?

Re: whos good w/ conditional probability?

Posted: Wed Mar 04, 2009 3:24 am
by DarkJackal
user wrote:where did you get 9/10 from?

108/120 reduced >.>?

Re: whos good w/ conditional probability?

Posted: Wed Mar 04, 2009 3:30 am
by ImmortalKiller
user wrote:
ImmortalKiller wrote:
user wrote:120 people: 95 bots, 108 plvls and 10 neither.

a. random person selected, what the probability the person either bots or plvls?
b. the person doesn't plvls, what is the probability he bot?
c. are botting and plvl independent events?


You are bad at explaining this, but I'll have a go.
I assume that you mean to imply:
Of the 95 bots and the 108 plvls, only 15 of the bots aren't PLVL'ing

no? there are 10 people who doesn't bot or plvl

Just draw a damn venn diagram, you suck at explaining.

Re: whos good w/ conditional probability?

Posted: Wed Mar 04, 2009 3:36 am
by DarkJackal
Are those the real answers in the topic post or what you got? Cus that doesn't seem right at all unless I just don't get it lol.

In which case I would agree with Immortal >;x.

Re: whos good w/ conditional probability?

Posted: Wed Mar 04, 2009 3:39 am
by Plutonium
user wrote:120 people: 95 bots, 108 plvls and 10 neither.

a. random person selected, what the probability the person either bots or plvls? 0.9167
b. the person doesn't plvls, what is the probability he bot? 0.4000
c. are botting and plvl independent events? yes

quote to review answers


a) 95+108/120 = 169%
b) 120-108-10/95 = 2.105%
c) yes obviously

Re: whos good w/ conditional probability?

Posted: Wed Mar 04, 2009 3:41 am
by user
DarkJackal wrote:Are those the real answers in the topic post or what you got? Cus that doesn't seem right at all unless I just don't get it lol.

In which case I would agree with Immortal >;x.

yea they are from the answer key, i am trying to figure them out as well. there is no venn diagram provided

@Plutonium in probability, max is 100, min is 0

Re: whos good w/ conditional probability?

Posted: Wed Mar 04, 2009 4:09 am
by ImmortalKiller
user wrote:
DarkJackal wrote:Are those the real answers in the topic post or what you got? Cus that doesn't seem right at all unless I just don't get it lol.

In which case I would agree with Immortal >;x.

yea they are from the answer key, i am trying to figure them out as well. there is no venn diagram provided

@Plutonium in probability, max is 100, min is 0

NO NO NO DUMBASS.

Probability is a number between 0 and 1.

PERCENT is a number between 0 and 100, hence the suffix CENT, meaning 100.

Just photocopy the question and I'll answer it. You've got about 20 minutes unless you've got time to wait a day. I was correct with A and C, who knows what led me to my answer for B

Re: whos good w/ conditional probability?

Posted: Wed Mar 04, 2009 8:23 pm
by Furious
A) 10 out of the 120 ppl don't bot or plvl, leaving 110 ppl who plvl and/or bot.
so 110 out of 120 either bots or plvls. (110/120)x100%= 91,67%

B) 108 out of 120 ppl does plvls. 10 ppl don't bot/plvl. so 118 out of 120 ppl either plvls or does neither. Leaving 2 out of 120 ppl who bot. (2/120)x100%= 1,67%

C) wut?

Re: whos good w/ conditional probability?

Posted: Wed Mar 04, 2009 8:36 pm
by ImmortalKiller
Furious wrote:A) 10 out of the 120 ppl don't bot or plvl, leaving 110 ppl who plvl and/or bot.
so 110 out of 120 either bots or plvls. (110/120)x100%= 91,67%

B) 108 out of 120 ppl does plvls. 10 ppl don't bot/plvl. so 118 out of 120 ppl either plvls or does neither. Leaving 2 out of 120 ppl who bot. (2/120)x100%= 1,67%

C) wut?

B is basically this:

Given that "SOMETHING" has occurred, what is the probability that "SOMETHING ELSE" has occurred?

The first portion of the question changes the denominator in your proportion.