Overview
This lecture explains how to calculate the mean and standard deviation of a sample dataset using the TI-84 calculator, including step-by-step entry and interpretation of results.
Entering Data into TI-84 Calculator
- Press
STAT then EDIT to access the data entry screen.
- Enter each data value into list L1, repeating values as necessary.
- Hit
ENTER after typing each value to record it.
- To clear existing data, highlight L1 (or another list) and press
CLEAR.
Calculating Mean and Standard Deviation
- After data entry, press
STAT, move to CALC, and select 1-Var Stats.
- Specify the list by typing
2nd then 1 for L1.
- Press
ENTER to perform the calculation.
- The mean (
x̄) is displayed; in the example, the mean is 11.55.
- Sample standard deviation (
Sx) is used for sample data; for the example, Sx = 3.45.
- Use
σx (sigma X) only if the data represents a population.
Verifying and Interpreting Results
- Check that
n (number of data values) matches your dataset for accuracy.
- Scroll down the output to find additional statistics such as minimum, maximum, and quartiles.
Key Terms & Definitions
- Mean (x̄) — The average value of the data set.
- Sample Standard Deviation (Sx) — Measures data spread in a sample.
- Population Standard Deviation (σx) — Measures spread if the entire population is used.
- n — The number of data values entered.
- 1-Var Stats — TI-84 function that provides statistics for one-variable data.
Action Items / Next Steps
- Practice entering and analyzing different data sets on the TI-84.
- Double-check entry to ensure the correct number of data points (
n) is used.