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HOW TO FIND TWO SAMPLE T CONFIDENCE INTERVALS USING DATA WITH TI83 CALCULATOR

Steps Key Sequence Screens
1. Enter data into list, L1    
2. Enter data into list, L2    
3. Set up Stats Tests STAT
  twice
  0 (for 2–SampTInt...)
4. Select Data use left arrow key (if necessary) to move cursor to Data, then ENTER
5. Select list, L1 (press ALPHA), then 2nd, then 1, then ENTER
6. Select list, L2 (press ALPHA), then 2nd, then 2, then ENTER
7. Input confidence level twice, enter confidence level (AS DECIMAL), then ENTER
8. Enter no for Pooled use left arrow key (if necessary) to move cursor to No, then ENTER
9. Calculate CI once, ENTER
10. Scroll down to find more calculations Press
In this case the 90% CI is 3.9676 to 9.1157.