Guide
for Determining the Confidence Interval Using the TI-83
1. Press the
button
and then the
button.
Put the data for the activity into the L1 column.
2. Press the
button
again and press the
button
twice to highlight TESTS at the top. Press the
button
until you reach choice 8 : TInterval. Press the
button.
3. Confirm that DATA is highlighted and L1 is next to LIST.
4. Press the
button
until CALCULATE is highlighted and then press the
button.
5. The screen will display the results of the confidence interval. Under the TINTERVAL there should be a set of two numbers, which show the confidence interval. The x shows the mean of the data and the Sx shows the standard deviation. The n equals the number of data points there are in the data set.
6. In order to calculate the actual confidence interval, subtract the first number in the set of of numbers under TINTERVAL from the mean value (x). This number is the confidence interval of the data set.
Original work on this document was done by Central Virginia Governor's School students Jennifer Rice, Eliza Evans, and Chris Earle (Class of '03).
Copyright © 2002 Central Virginia Governor's School for Science and Technology, Lynchburg, VA