How to calcualte for confidence interval for for standard deviation for given standard deviation and mean at 99 % using a TI 30 X IIS calculator

First you need the Std Error of the mean value, a measure of the dispersion of that mean value.

SE = sample std deviation / sqrt (sample size)
= 8 / ? 64
= 1

Then we use a figure for the number of std errors either side of the mean value, which make up a 99 % confidence interval. This is ± 2.58 std errors, from tables of the Normal Distribution.

So the confidence interval is

125 ± 2.58 * 1 or

127.58 to 122.42
.

If you mean the standard deviation, there are two shifted keys on the third row marked with a lower-case Greek sigma. sigma_xn is the population standard deviation and sigma_xn-1 is the sample standard deviation.

There isn't one. Press the "STAT VAR" button to bring up the statistics menu. "Sx" and "Sy" will give you the sample standard deviations, while "sigma x" and "sigma y" will give you the population standard deviations.

When I say "sigma" I mean the lower case Greek letter sigma, which looks like a lower-case "o" with a tail pointing to the right.

Press 2nd [STAT] then select CLRDATA to clear statistics data. Select 1-VAR or 2-VAR for one-variable or two-variable statistics. Press DATA and enter your data (x for 1-VAR or x and y for 2-VAR). Press 2nd [EXIT-STAT] and select N. Press STAT-VAR to see a menu of statistics variables and their values. Sx (and Sy) will give you the standard deviation, sigma-x (and sigma-y) will give you the population standard deviation.

You can calculate the mean by dividing the total 32.4 by the number of entries (6). That is all you can do. You need the actual numbers (data) to get the standard devistion.

Press 2ND [CSR] to clear the stat data.

For each data point, enter the number followed by SIGMA+

If you have grouped data, enter the number followed by 2ND [FRQ] followed by the frequency then SIGMA+

Press 2ND [sigma x n] for the population standard deviation or 2ND [sigma x n-1] for the sample standard deviation.

Hello,
I know that you can do 1 and 2 variable statstics, several kinds of regressions analyses, forecasting a value, make statistical graphs. I give you a link to the manual, which you will read to see if the calculator perfoms the calculations you refer to.

http://education.ti.com/educationportal/downloadcenter/SoftwareList.do?website=US&tabId=2&paneId=17

Hope it helps.

1 - .93 = .07/2 = .035

Texas Instruments TI-86 Statistics How-To Information The following instructions should allow you to calculate the mean and standard deviation using a TI-86 calculator.

1. Press STAT
2. Select EDIT
3. Enter data into a list: [2.32 ENTER 2.43 ENTER 2.39 ENTER, etc.] Continue until all data have been entered. (use arrows keys to go to the y value, if any)
   
4. EXIT until you reach the main ("blank") screen. (If you try to calculate while you're in the data menu, it thinks you're still trying to enter data!)
5. Press STAT
6. Select CALC
7. Select OneVa
8. Select LIST, NAMES, xStat(F2), Press ENTER
9. The calculator provides Max, Min, Mean, Standard Deviation, Sum, Sigma, etc. You will be primarily interested in the Mean and Standard Deviation (sx).

StdDev( {1,2,3,4,5,6,7,8,9,10} )
with your list inside the curly braces.