# Binomial Distribution

• Jun 20th 2010, 09:16 AM
Apprentice123
Binomial Distribution
Calculate the binomial distribution for
n = 14 e p = 0,60, find P(X < 9)

P(X < 9) = 1 - P(X > 9) ????
• Jun 20th 2010, 09:31 AM
Unknown008
No, P(X < 9) means all the values of X that X can take that is less than nine, excluding 9. This means you have X = 0, 1, 2, 3, 4, 5, 6, 7, 8.

But for P(X > 9), you have X = 10, 11, 12, 13, 14.

But 1 - P(X > 9) incluse the values of X = 0, 1, 2, 3, 4, 5, 6, 7, 8, 9.

which is not equal to P(X < 9)
• Jun 20th 2010, 11:49 AM
chisigma
Is...

$\displaystyle \displaystyle P(k<9) = \sum_{k=0}^{8} \binom {14}{k} .6^{k} \ .4^{14-k}$ (1)

Kind regards

$\displaystyle \chi$ $\displaystyle \sigma$
• Jun 20th 2010, 01:10 PM
Apprentice123
If I have 11 elements, is easy calculate
P(X<9) = 1 - P(X>=9)

I can ?
• Jun 20th 2010, 01:21 PM
SpringFan25
yes
• Jun 20th 2010, 01:24 PM
undefined
Quote:

Originally Posted by Apprentice123
If I have 11 elements, is easy calculate
P(X<9) = 1 - P(X>=9)

I can ?

In this case,

P(X<9) = 1 - P(X=9) - P(X=10) - P(X=11)

(I assume having 11 elements means there are 11 experiments/trials.)
• Jun 20th 2010, 01:45 PM
Apprentice123
Thanks