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seen Sep 13 '13 at 23:49

Oct
17
revised Why is the greatest and least values for each group in these 2 frequency distribution unknown?
added 8 characters in body
Oct
17
asked Why is the greatest and least values for each group in these 2 frequency distribution unknown?
Oct
17
accepted Calculating Variance of a binomial distribution using the standard formula $E(X^2) - \mu^2$
Oct
17
comment Calculating Variance of a binomial distribution using the standard formula $E(X^2) - \mu^2$
is that correct?
Oct
17
comment Calculating Variance of a binomial distribution using the standard formula $E(X^2) - \mu^2$
$P(X=0) = {20 \choose 0}(0.5)^0(0.5)^{20}, P(X=1)={20 \choose 1}(0.5)(0.5)^{19}, P(X=2)={20 \choose 2}(0.5)^2(0.5)^{18}$ etc etc?
Oct
17
comment Calculating Variance of a binomial distribution using the standard formula $E(X^2) - \mu^2$
i think you've posted how $np(1-p)$ is derived, but can you show me how you'd substitute the numbers from this particular question (20 games 0.5 chance of winning). you don't have to write all 20, just write the first few then use "dot dot dot" ...
Oct
17
comment Calculating Variance of a binomial distribution using the standard formula $E(X^2) - \mu^2$
@Max you are correct. I made the correction. thank you
Oct
17
revised Calculating Variance of a binomial distribution using the standard formula $E(X^2) - \mu^2$
added 14 characters in body
Oct
17
asked Calculating Variance of a binomial distribution using the standard formula $E(X^2) - \mu^2$
Oct
11
accepted By convention $P[X=x] = 0$ for all x. How would you explain pdf $f(x) =3x^2$ (where x is between 0 and 1) when x =0.9
Oct
11
comment By convention $P[X=x] = 0$ for all x. How would you explain pdf $f(x) =3x^2$ (where x is between 0 and 1) when x =0.9
@AndréNicolas i understand that part. but do you know what does $f(0.9)$ yield?
Oct
11
comment By convention $P[X=x] = 0$ for all x. How would you explain pdf $f(x) =3x^2$ (where x is between 0 and 1) when x =0.9
@chris ok, i see. then what do i get when I plug in 0.9 for x?
Oct
11
revised By convention $P[X=x] = 0$ for all x. How would you explain pdf $f(x) =3x^2$ (where x is between 0 and 1) when x =0.9
added 3 characters in body
Oct
11
comment By convention $P[X=x] = 0$ for all x. How would you explain pdf $f(x) =3x^2$ (where x is between 0 and 1) when x =0.9
ok, when $x =0.9$ then $f(0.9)= 3(0.9)^2 which \neq 0$. That's what I'm trying to ask
Oct
11
asked By convention $P[X=x] = 0$ for all x. How would you explain pdf $f(x) =3x^2$ (where x is between 0 and 1) when x =0.9
Oct
10
revised How can gender and class classification be dependent?
edited title
Oct
10
comment How can gender and class classification be dependent?
Ross, thank you for your answer! I upvoted everyone who contributed, honestly I still don't quite get it. but it's pretty late tonight. I'll think more on each answer when i wake up tomorrow morning.
Oct
10
comment How can gender and class classification be dependent?
oh no =( this is so convoluted. I started a post before on how I can identify a probability problem as a conditional probability problem(math.stackexchange.com/questions/205103/…). it seems like you're suggesting they're the same. this is still confusing =(
Oct
10
comment How can gender and class classification be dependent?
why would you think of this in terms of conditional probability? I'm thinking it's simple union and interects
Oct
9
revised How can gender and class classification be dependent?
deleted 7 characters in body