 # Calculating expected mean and SD on TI BA plus

Hi all, I was wondering are we able to calculate SD and Mean of expected data (probability given) using TI BA plus calculator? Thanks S

nope sorry not that i know of

Put it in the data (2nd 7key) and then go to 2nd stat (the 8 key) Check your manual.

I wish getterdone!!! Actually you can do an x and y but I don’t think it pertains to our ridiculous portfolio std. equation we need to memorize.

it doesn’t, back in January I tried for about a week to do it but there is no way. But I feel really good about those formulas now, or else I would have reprogrammed my calc to do it I use it for all stat questions… If you only have one data set (not just x and y) just leave the Y’s blank.

how about in terms of probability if i was have probability 1=30% 2=20% 3=50% how would you calculate expected value and variance on the calculator i know you can do it by going X1,X2,X3 = 1 X4,X5=2 X6,X7,X8,X9,X10=3 but are there ways to just input the probability?

xck2000 Wrote: ------------------------------------------------------- > how about in terms of probability > > if i was have probability 1=30% 2=20% 3=50% how > would you calculate expected value and variance on > the calculator > > i know you can do it by going > > X1,X2,X3 = 1 X4,X5=2 X6,X7,X8,X9,X10=3 > > but are there ways to just input the probability? I think, 2nd DATA and you input X for the value and y for the probability

You are right, if you enter the probabilities as Y values, you can get the expected value. You can calculate the standard deviation correctly if the probabilities of all occurences are equal.

No you can’t enter probabilities in the Y values to get standard deviation. It works with all occurences being equal… but then that’s the definition of just your normal run-of-the-mill standard deviation where you divide by n. So really you’d get the same answer not entering the Y values in.

Guys, pls look up Statistics Worksheet Variables in your manual, or download one in this link, education.ti.com/downloads/guidebooks/financial/baiiplus/BAIIPLUSGuidebook_EN.pdf 1.Key in a value for Y01 • For one-variable data, you can enter the number of times the X value occurs (frequency) in corresponding Y. The default value is 1. • For two-variable data, enter the first Y value. 2. Analyzing One-Variable Statistics To analyze one-variable statistics, select 1-V. Only values for n, v, Sx, sX, GX, and GX2 are computed and displayed for one-variable statistics. after [2nd]&[STAT],you have to Press [2nd]& [SET] repeatedly until the statistics calculation method you want is displayed. If you are analyzing one-variable data, select 1-V. I used above sample: i was have probability 1=30% 2=20% 3=50% E(i)=2.2 within 15 seconds. this is a great post, I used to input X value 10 times instead of use Y as frequency. it may save my time in real time. thanks!