I am trying to solve binomial probability questions but I cannot find binompdf nor binomcdf on my TI-89 Titanium. Do you know how I could calculate those problems using my TI-89 Titanium?

If the probability of passing the driving test is 0.8, then the probability of exactly 11 people passing the test out of 200 candidates is less than 1 in 10^100, which is zero as far as the calculator is concerned. Is this what you're trying to calculate?

If you want to know the probability that 11 or more people have passed, then you want 1-binomcdf(200,.8,10) which will give you 1 since the probability of 10 or fewer passing is zero.

Think about it. If you have a group of 200 adults, how likely is it that only 11 of them have driver's licenses?

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

At first, APPS and then Statistics with List Editor. See capture image below

Press 2nd Math -> More -> Stat -> DI ST -> More -> bipdf(

Use the catalog.
The CATALOG key is below the APPS key on the TI-89

Using elementary algebria in the binomial theorem, I expanded the power (x + y)^n into a sum involving terms in the form a x^b y^c. The coefficient of each term is a positive integer, and the sum of the exponents of x and y in each term is n. This is known as binomial coefficients and are none other than combinatorial numbers.

Combinatorial interpretation:

Using binomial coefficient (n over k) allowed me to choose k elements from an n-element set. This you will see in my calculations on my Ti 89. This also allowed me to use (x+y)^n to rewrite as a product. Then I was able to combine like terms to solve for the solution as shown below.
(x+y)^6= (x+y)(x+y)(x+y)(x+y)(x+y)(x+y) = x^6+6x^5y+15x^4y^2+20x^3y^3+15x^2y^4+6xy^5+y^6

This also follows Newton's generalized binomial theorem:



Now to solve using the Ti 89.

Using sigma notation, and factorials for the combinatorial numbers, here is the binomial theorem:

The summation sign is the general term. Each term in the sum will look like that as you will see on my calculator display. Tthe first term having k = 0; then k = 1, k = 2, and so on, up to k = n.
Notice that the sum of the exponents (n ? k) + k, always equals n.






The summation being preformed on the Ti 89. The actual summation was preformed earlier. I just wanted to show the symbolic value of (n) in both calculations. All I need to do is drop the summation sign to the actual calculation and, fill in the term value (k), for each binomial coefficient.





This is the zero th term. x^6, when k=0. Notice how easy the calculations will be. All I'm doing is adding 1 to the value of k.




This is the first term or, first coefficient 6*x^5*y, when k=1.
Solution so far = x^6+6*x^5*y






This is the 2nd term or, 2nd coefficient 15*x^4*y^2, when k=2.
Solution so far = x^6+6*x^5*y+15*x^4*y^2







This is the 3rd term or, 3rd coefficient 20*x^3*y^3, when k=3.
Solution so far = x^6+6*x^5*y+15*x^4*y^2+20*x^3*y^3







This is the 4th term or, 4th coefficient 15*x^2*y^4, when k=4.
Solution so far = x^6+6*x^5*y+15*x^4*y^2+20*x^3*y^3+15*x^2*y^4






This is the 5th term or, 5th coefficient 6*x*y^5, when k=5.
Solution so far = x^6+6*x^5*y+15*x^4*y^2+20*x^3*y^3+15*x^2*y^4+6*x*y^5





This is the 6th term or, 6th coefficient y^6, when k=6.
Solution so far = x^6+6*x^5*y+15*x^4*y^2+20*x^3*y^3+15*x^2*y^4+6*x*y^5+y^6





Putting the coefficients together was equal or, the same as for when I used the expand command on the Ti 89.

binomial coefficient (n over k) for (x+y)^6
x^6+6*x^5*y+15*x^4*y^2+20*x^3*y^3+15*x^2*y^4+6*x*y^5+y^6

Having gone over a month with no response, I assume this is no longer a problem.

Do you have the Stats/List-Editor app loaded? If not, you can download it from http://education.ti.com

You can also try StatLite, available from http://www.ticalc.org

Hello,
Press the yellow [2nd] key then [VARS] (DISTR) to access the distributions. Scroll Up or down to see 0:binompdf( . Press 0 |ENTER|. The command echoes on the screen as binompdf(. Complete the command by entering the number of trials, the probability of success, and the value expected. Number of trials, and the value expected are integers.
You can also run the command giving it a sequence of expected values. In that case the sequence of expected values must be enclosed in curly brackets
Hope it helps.
binompdf ( number of trials, p, { expec_value1, expec_value2, ...} ) [ENTER]

If you connect calculator to computer using Ti connect device explorer you might be able to see what files are on the calculator. I don't know if you downloaded from the web but, 3rd party programs and shells tent to miss up the calculator. This would able you to delete out possible problems which could be re installed later.