Math Is Fun Forum
  Discussion about math, puzzles, games and fun.   Useful symbols: √ ∞ ≠ ≤ ≥ ≈ ⇒ ∈ Δ θ ∴ ∑ ∫ π -

Login

Username

Password

Not registered yet?

Post a reply

Go back

Write your message and submit
:) :| :( :D :o ;) :/ :P :lol: :mad: :rolleyes: :cool: | :dizzy :eek :kiss :roflol :rolleyes :shame :down :up :touched :sleep :wave :swear :tongue :what :faint :dunno
Options

Go back

Topic review (newest first)

bobbym
2013-12-10 20:49:58

Hi;

You can get a probability from the odds.

extjsjquery
2013-12-10 14:39:08

Tks for your reply.  I input a wrong number that Number in 1st group:    a=26
  not 25    if 25  ,2 .777  is  right.
like formula Odds ratio = (a/c) / (b/d) ,what is the formula for probability?

bobbym
2013-12-10 03:42:17

Hi;

Are you doing something like this?

http://www.youtube.com/watch?v=ITi0SxmQTO8

I am getting an OR = 2.7777777777

Also I think you mean P rather than p.

Z scores are measures of standard deviation. P is a probability.

extjsjquery
2013-12-10 03:31:33

I input a,b,c,d  use odds ratio calculator

Cases with positive outcome
Number in 1st group:    a=25
Number in 2nd group:    b=15
Cases with negative outcome
Number in 1st group:    c=18
Number in 2nd outcome:    d=30

and calculate

Results
Odds ratio    2.8889
95 % CI    1.2184 to 6.8497
z statistic    2.408
P = 0.0160

I know odds ratio is Odds ratio = (a/c) / (b/d)
my question is
what z statistic    and p mean ?

Board footer

Powered by FluxBB