any other hmt member know anything about college statistics?
 

so i have a take home test in my statistics class and i cant figure out how to set up this problem... i mean it seems easy but i have tried everything to get the answer and i cant! every answer i come up with isn't one of the four answers my professor gave me see if you can figure it out

if a student randomly guesses at 20 multiple choice questions, find the probability that the student gets exactly four correct. each question has four possible choices


a .19
b .17
d .08
c .23

Re: any other hmt member know anything about college statistics?
 

its factorials, i would do it for you but i dont have my calc with me.

Re: any other hmt member know anything about college statistics?
 

haha... sucks for you i have a bad memory... it's an easy question... too bad I forgot how to do them... I just remember doing them and they were cake...

Re: any other hmt member know anything about college statistics?
 

i'd guess .20 but thats not one of your answers :P

Re: any other hmt member know anything about college statistics?
 

C

Re: any other hmt member know anything about college statistics?
 

its

a

Re: any other hmt member know anything about college statistics?
 

its the secret answer

e: suck my nuts

Re: any other hmt member know anything about college statistics?
 

I know one thing for sure, Petey has a 25% chance of being right just by guessing.

Re: any other hmt member know anything about college statistics?
 

I just noticed your letters go

a
b
d
c

What kind of crazy college you go to, nog?

Re: any other hmt member know anything about college statistics?
 

I got a B in that class.

Re: any other hmt member know anything about college statistics?
 

lol this is not to bad, if there are 4 choices and he is randomly guessing then he has a 25% prob to answer each one correctly 1 out of 4. If he answers 2 of these by guessing then his odds are .25*.25 = .0625 or 6.25% chance of getting them both, if he answers 4 its (.25)^4 or .0039
.39% chance of getting 4 right. Its important to note if he can narrow it down to a 50/50 this helps alot.
*edit* I though about it a bit more and I think the odds are lower then .0039, because he would also have to get the other 16 questions wrong. .75^16= .010. The probability of two independent events happening is found by multiplying them so .010*.0039= .000039 or .0039%. Looks like this isn't one of your choices, I may be wrong let me know how he shows you to do it.