PakMediNet Discussion Forum : Biostatistics : variance
variance
please anybody explain why do we multiply P with 1-p and then divide it with n to calculate the variance and standard deviation for proportion in population. that is
p(1-p)\n is equal to sigma square. why this p * q where q = 1-p...
confused.
Posted by: angel73Posts: 11 :: 10-06-2010 :: | Reply to this Message
Re: variance
p= indicate success
and Q= no success
ok in stats if u want to take oposite then we use 1- ok
for exp oposite of p is 1-p that is equal to q. q is just notation u can say may be S R etc ok p and q is world wide stats notation p mean success and q mean no success
next question is y divide it with n its a probability to get probability we always divide it with whole pop ok and sigma is the notation that mean stander deviation ok
Posted by: RaliPosts: 5 :: 06-08-2010 :: | Reply to this Message
Re: Re: varianceTHE FORMULA TO CALCULATE SE OF PROPORTION IS AS YOU WRITTEN IN
Posted by: ibrahim_apPosts: 138 :: 06-08-2010 :: | Reply to this Message
Re: varianceAre you asking why we divide standard deviation by sqrt(n) to get standard error?
Posted by: rqayyumPosts: 199 :: 19-11-2010 :: | Reply to this Message