Main Index >

TI 83 > TI 83 Confidence Interval Population Mean

This article shows you the steps for TI 83 Confidence Interval (Population Mean).

You might also be interested in:

## Ti 83 Confidence Interval Population Mean: Overview

The **TI 83 graphing calculator** can help you figure out just about every **confidence interval problem** you come across in elementary statistics. The confidence interval is a range of data that you expect values to fall between. A simple example: you might expect your weekly paycheck to be between $500 and $600. The only difference between having “Stats” (statistics such as mean, or standard deviation) or “Data” (the actual raw, data), is that you will have to enter the data into a list in order to perform the calculation. If you don’t know how to enter the data is entered into a list, you can find the information in this article on cumulative frequency tables.

## TI 83 Confidence Interval Population Mean: Steps

Watch the video or read the steps below:

## Confidence intervals for the population mean

Sample problem: 40 items are sampled from a normally distributed population with a sample mean x̄ of 22.1 and a population standard deviation(σ) of 12.8. Construct a 98% confidence interval for the true population mean.

**Step 1**: Press STAT, then right arrow over to “TESTS.”

**Step 2**: Press 7 for “Z Interval.”

**Step 3**: Arrow over to “Stats” on the “Inpt” line and press ENTER to highlight and move to the next line, σ.

**Step 4**: Enter 12.8, then arrow down to x̄.

**Step 5**: Enter 22.1, then arrow down to “n.”

**Step 6**: Enter 40, then arrow down to “C-Level.”

**Step 7**: Enter .98. Arrow down to “calculate” and then press ENTER. The calculator will give you the result of (17.392, 26.808) meaning that your 98% confidence interval is **17.392 to 26.808**. This is the same as:

17.392 > μ > 26.808

That’s how to make a TI 83 Confidence Interval Population Mean!

**Lost your guidebook**? Download a new one here from the TI website.

**Questions?** Ask on our FREE forum. Our resident stats guy will be happy to answer those tricky stats problems.

Check out our Youtube channel for more stats help and tips!

Currently in statistics class we are working with z scores. My table only goes up to 3 or 3.5.I’m suppose to find the z score for the number 7 on my TI-83 but can’t find the info in the practically cheating handbook. Can you help? Thank you.

Brigette,

Any z-score greater than about 3.5 is going to have an are of about 4.9999.

For the TI-83, On the TI-83, the functions are

normalcdf(left,right,[mu,sigma]) finds the area under the normal curve (This function is listed under the “Distru” menu.)

Regards,

Stephanie

P.S. You can always check out our forums for any stats question :)

http://www.statisticshowto.com/forums/