Calculators TI-89 Titanium - Probability - Expected Value

[rekshaw]

EDIT: I found the solution, it can be done using the TwoVar() function on the TI-89 and it gives you a whole lot more than just the expected value. thanks anyways

Hello everyone! :)

I hope I will get an answer for this!

As a USER-DEFINED function I would like to be able to calculate the Expected Value of n outcomes with their respective probabilities (also in a single matrix)

it should look something like this:

\begin{pmatrix}<br /> <br /> 1 &amp; 1/6 \\<br /> 2 &amp; 1/6 \\<br /> 3 &amp; 1/6 \\<br /> 4 &amp; 1/6 \\<br /> 5 &amp; 1/6 \\<br /> 6 &amp; 1/6 \end{pmatrix}

To find the expected value I would need to do:

(1 \times 1/6) + (2 \times 1/6) + ... + (6 \times 1/6) = E(X)

Basically, multiply each outcome with its probability and finally sum the whole lot...

IDEALLY...I would like to be able to make a single 2 x n matrix with outcomes and probabilities side-by-side, store it as A and be able to do:

expval(A)

or...which is faster to type: make a n*2 matrix!

Anyways...sorry for the long post, any help will be much appreciated!

 

[Mark44]

Nice solution!