Binomial distribution How to calculate probability of a binomial function

The only known equation for the cumulative binomial distribution is the sum of the individual binomial probabilities. Some more sophisticated (and more expensive) calculators have that equation built in, but the 30xii does not.

If n>30 and n*p>5 and n*(1-p)>5 then you can approximate the cumulative binomial with the normal probability function, but again the 30xii does not have that built in.

The number of combinations of n objects taken r at a time has a reserved symbol nCr. On calculators it has a special key (or shifted key) marked nCr.
By definition nCr=(n!)/((r!)*(n-r)!)=nC(n-r)
In what follows, I am using parentheses to enclose what is in the denominators). So
10!/(8!2!)=10C2 or 10C8 =45 (they have the same value)
10!/(9!1!)=10C9=10C1=10
10!/(10!0!)=1

Do you have a question about the binomial probability distribution function or the binomial cumulative distribution function?

See cap images below

There are a lot of probability distributions: binomial, chi-square, F, normal, poisson, and t, just to name a few. Do you have a particular one in mind?

Hello,

The binomial probability distribution is defined as
P(r;p;n) =(nCr)(p^r)*(1-p)^(n-r)
where n is the number of trials, p the probability of success, and r the expected result.

Let n=20, r=7, p=0.15 ( I do not know wether this exemple has any meaning in the context of your problem, but you have to enter values that mean something to you. I am only showing you the key strokes

To enter 20C7 you press 20 [SHIFT][nCr]7 ;
To enter 0.15 to the power 7 you type 0.15[X to ] 7 the key is between
[x²] and [log]

To enter (1-0.15) to power 20-7, you type 0.85 [X to] 13
With [*] standing for multiplication key , and [X to] the raise to power key, the exemple above can be entered as

( 20 [SHIFT][nCr] 7) [*] ( 0.15 [X to] 7 ) [*] ( 0.85 [X to] 13 ) [=]

Here is a screen capture to show you what it looks like. However on this calculator the combination 20 [SHIFT][nCr] 7 is represented as nCr(20,7).



Hope it helps

Hello,

The binomial probability distribution is defined as
P(r;p;n) =(nCr)(p^r)*(1-p)^(n-r)
where n is the number of trials, p the probability of success, and r the expected result.

Let n=20, r=7, p=0.15 ( I do not know wether this exemple has any meaning in the context of your problem, but you have to enter values that mean something to you. I am only showing you the key strokes

To enter 20C7 you press 20 [SHIFT][nCr]7 ;
To enter 0.15 to the power 7 you type 0.15[X to ] 7 the key is between
[x²] and [log]

To enter (1-0.15) to power 20-7, you type 0.85 [X to] 13
With [*] standing for multiplication key , and [X to] the raise to power key, the exemple above can be entered as

( 20 [SHIFT][nCr] 7) [*] ( 0.15 [X to] 7 ) [*] ( 0.85 [X to] 13 ) [=]

Here is a screen capture to show you what it looks like. However on this calculator the combination 20 [SHIFT][nCr] 7 is represented as nCr(20,7).



Hope it helps

Hello,

Sorry, but you information is wrong, to find the binomial distribution use the PROB menu not the STAT menu. Its name is randBi
[2nd][MATH][F2:PROB] scroll right.
Hope it helps.

Yes, eleven million is rather extreme for the binomial distribution. For this large a value the binomial distribution is sufficiently indistinguishable from the normal approximation.

Hello,
Let us start with a review of the formula for the binomial distribution
f(r;n,p)=n!/(r!(n-r)!)x(p^r)x(1-p)^(n-r)

But n!/(r!(n-r)!)=(nCr) you get
f(r;n,p)= (nCr)x(p^r)x(1-p)^(n-r)

Exemple : n=25, r=6, p=0.7

f(6;25,0.7)= 25 [PRB] [-->] 6 [ x ] {0.7[ ^] 6 }[ x ]{0.3[ ^ ]19}

The arrow means a horizontal scroll once to select the (nCr) function. [ x ] stands for the multiplication sign.
[ ^] is the raise to the power key
The { } are used here as parentheses to make formula legible.

Hoe it helps

Hope it helps

Hope it helps.