Use TI-84 Online for Statistics
The TI-84 graphing calculator is the gold standard for statistics courses. From descriptive statistics to regression analysis, here's how to use the TI-84 (or our free online emulator) for all your statistics needs.
Descriptive Statistics (1-Var Stats)
To calculate mean, median, standard deviation, and quartiles for a data set:
Enter Data
Press STAT → 1: Edit. Enter your data values in list L1. Press ENTER after each value.
Run 1-Var Stats
Press STAT → scroll right to CALC → 1: 1-Var Stats. Select L1 and press ENTER.
Read Results
You'll see: x̄ (mean), Σx (sum), Sx (sample std dev), σx (population std dev), n (count). Scroll down for min, Q1, Med (median), Q3, max.
Linear Regression
To find the line of best fit for two-variable data:
- Enter x-values in L1 and y-values in L2
- Press STAT → CALC → 4: LinReg(ax+b)
- Select L1, L2, and optionally store the equation in Y1
- Press ENTER — you get a (slope), b (intercept), and r² (coefficient of determination)
Other regression types available: QuadReg, CubicReg, QuartReg, ExpReg, LnReg, PwrReg, Logistic, SinReg.
Normal Distribution
Key functions for the normal distribution:
- normalcdf(lower, upper, μ, σ) — Probability between two values
- invNorm(area, μ, σ) — Find the z/x value for a given probability
- normalpdf(x, μ, σ) — PDF value (for graphing the bell curve)
Access these via 2ND → VARS (DISTR).
Example: Finding P(60 < X < 80) for μ=70, σ=10
- Press 2ND → VARS → 2: normalcdf(
- Enter:
normalcdf(60, 80, 70, 10) - Result:
0.6827(about 68.3%)
Hypothesis Testing
The TI-84 has built-in hypothesis test functions:
- Z-Test — One-sample z-test for means
- T-Test — One-sample t-test
- 2-SampZTest — Two-sample z-test
- 2-SampTTest — Two-sample t-test
- 1-PropZTest — One-proportion z-test
- 2-PropZTest — Two-proportion z-test
- χ²-Test — Chi-square test
- LinRegTTest — Linear regression significance test
Access all tests via STAT → TESTS.
Confidence Intervals
Available under STAT → TESTS:
- ZInterval — For known σ
- TInterval — For unknown σ (most common)
- 1-PropZInt — For proportions
- 2-SampZInt / 2-SampTInt — For comparing two groups
Statistical Plots
The TI-84 can create various statistical plots:
- Scatter plot — X-Y data visualization
- Histogram — Frequency distribution
- Box plot — Five-number summary visualization
- Normal probability plot — Check if data is normally distributed
Access via 2ND → Y= (STAT PLOT). Select Plot1, turn it ON, choose plot type, and set data list.
AP Statistics Exam Tips
💡 On the AP Stats exam, you MUST show your work. The TI-84 gives you the answer, but you need to write the hypotheses, conditions, test statistic, p-value, and conclusion. Use the calculator to compute — then interpret clearly.
FAQ
Yes! The TI-84 is the most popular calculator for AP Stats. It handles all required operations: 1-Var Stats, regression, normalcdf, invNorm, hypothesis tests, and confidence intervals.
Press 2ND → 0 (CATALOG). Scroll to DiagnosticOn and press ENTER twice. Now r and r² will display with regression results.