4 replies to this topic

[ZuzaMagda]

How to calculate binomial coefficients and binomial distribution on a Casio fx-9860G?

[barry2718]

How to calculate binomial coefficients and binomial distribution on a Casio fx-9860G?

The binominal coefficient are calculated using the "C" or combinatorial values.
e.g for a trial of 4 EVENTS you expand (p+q)^4 = 4C0p^0q^4 + 4C1p^1q^3 + 4C2p^2q^2 + 4C3p^3q^1 + 4C4p^4q^0
where p is the probability of the event occurring and q = 1-p (event NOT occurring).
NB the coefficients of the p and q add up to 4 (number of trials).

You find the 'C' function under the CATALOG in the c's . It is the fat looking C.
e.g 4C2 --> gives a 6, 4C1 and 4C3 gives a 4, 4C0 and 4C4 gives a 1

the combinatorial is evaluated as nCa = n!/((n-a)!*(a!)) where n! is n factorial = n*(n-1)*(n-2)*....(2)*(1)

Also search on wikipeadia for pascals triangle.

[ZuzaMagda]

OK. Well, I do understand Pascal's triangle, etc., etc., and I know how to calculate the binomial coefficient without the calculator (5C2 is basically 5!/(2!*3!), etc.); however, I would like to know how to do it on my calculator so I don't have to waste time doing the calculations on paper.

Thanks for the information that I can find the C function under the CATALOG. However, you say "under the CATALOG in the c's". HOW TO SEARCH FOR FUNCTIONS IN THE CATALOG? I don't know how to find "the c's", so what I do is use the arrow to move down the list and it takes 3 times as long as calculating nCr by hand takes me

Now, BINOMIAL DISTRIBUTION:

I throw a die n times and I want to calculate the probability of obtaining exactly r 4's.
I can do it using the formula:

nCr*(probability of obtaining a 4 = 1/6)^r*(probability of obtaining "not 4" = 5/6)^(n-r).

However, it takes a very long time even if I use the calculator to obtain my nCr (which is the least time-consuming part of the calculations anyway!). How to "automatize" it a bit? I know it is very easy on a Texas...

Edited by ZuzaMagda, 09 January 2011 - 08:42 AM.

[pan.gejt]

ad Binomial Distribution
Go to "Menu" - select "STAT" - select "DIST" (under F5) - select "BINM" (under F5). The following 3 items appear:
Bpd, Bcd and InvB.
Bpd- probability distribution
Bcd- cumulative probability distribution
InvB- inverse distribution

Based on your example, select the first item- Bpd. Do not forget to change inputting the DATA from "List" to "Variable" (F2)

[ZuzaMagda]

Thanks, that's just what I needed! I have even found out how to find functions in the CATALOG, so I counsider all my doubts to have been resolved