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๐Ÿ”ข TI-84 Cheat Sheet

Exact key sequences for every function you'll need on May 7.

๐Ÿ”” Normal Distribution

normalcdf โ€” area under curve
2nd VARS โ†’ 2: normalcdf(
normalcdf(lower, upper, ฮผ, ฯƒ)
lower/upper: bounds of the region
ฮผ: mean  |  ฯƒ: standard deviation
Use โˆ’1E99 or 1E99 for โˆ’โˆž / +โˆž
โœ“ Use for P(X < a), P(a < X < b), p-values
invNorm โ€” find the boundary value
2nd VARS โ†’ 3: invNorm(
invNorm(area, ฮผ, ฯƒ)
area: cumulative area to the LEFT
ฮผ: mean  |  ฯƒ: standard deviation
โœ“ Use for critical values z* and finding percentiles
tcdf โ€” t-distribution area
2nd VARS โ†’ 5: tcdf(
tcdf(lower, upper, df)
df: degrees of freedom (n โˆ’ 1 for 1-sample t)
โœ“ Use to find p-value manually from a t-statistic

๐Ÿ“Š Inference for Proportions

1-PropZTest
STAT โ†’ TESTS โ†’ 5: 1-PropZTest
pโ‚€: claimed proportion (Hโ‚€ value)
x: number of successes  |  n: sample size
Choose tail: โ‰ pโ‚€ / <pโ‚€ / >pโ‚€
โœ“ Gives z-statistic and p-value
1-PropZInt
STAT โ†’ TESTS โ†’ A: 1-PropZInt
x: successes  |  n: sample size  |  C-Level: confidence level (e.g. .95)
2-PropZTest
STAT โ†’ TESTS โ†’ 6: 2-PropZTest
x1, n1: group 1 successes & size
x2, n2: group 2 successes & size
2-PropZInt
STAT โ†’ TESTS โ†’ B: 2-PropZInt

๐Ÿ“ Inference for Means

T-Test (1-sample)
STAT โ†’ TESTS โ†’ 2: T-Test
ฮผโ‚€: claimed mean  |  xฬ„: sample mean
Sx: sample SD  |  n: sample size
Or choose Data and point to a list
โœ“ For paired data: enter differences in L1, use Data mode
TInterval (1-sample)
STAT โ†’ TESTS โ†’ 8: TInterval
2-SampTTest
STAT โ†’ TESTS โ†’ 4: 2-SampTTest
Enter stats for both groups  |  Pooled: No (always)
2-SampTInt
STAT โ†’ TESTS โ†’ 0: 2-SampTInt
Pooled: No always

๐Ÿ”ข Chi-Square Tests

ฯ‡ยฒ-Test (Independence / Homogeneity)
STAT โ†’ TESTS โ†’ C: ฯ‡ยฒ-Test
Step 1: Enter observed counts in matrix [A]
2nd xโปยน โ†’ EDIT โ†’ [A] โ†’ enter dimensions โ†’ enter counts
Step 2: Run ฯ‡ยฒ-Test โ€” it fills expected counts in [B] automatically
โœ“ Check [B] to verify all expected counts โ‰ฅ 5
ฯ‡ยฒGOF-Test (Goodness of Fit)
STAT โ†’ TESTS โ†’ D: ฯ‡ยฒGOF-Test
Enter observed counts in L1
Enter expected counts in L2
df = number of categories โˆ’ 1

๐Ÿ“ˆ Regression

LinRegTTest (inference for slope)
STAT โ†’ TESTS โ†’ E: LinRegTTest
Enter x in L1, y in L2
Choose tail (ฮฒ & ฯ: โ‰ 0 / <0 / >0)
Gives: a, b, s, r, rยฒ, t, p-value, df
โœ“ This is the one to use for Unit 9 inference
LinReg(a+bx) โ€” LSRL equation only
STAT โ†’ CALC โ†’ 8: LinReg(a+bx)
Enter Xlist: L1, Ylist: L2
Gives: a (y-intercept), b (slope), r, rยฒ
โœ“ Use this when you only need the equation, not inference

๐Ÿ“‹ Data Entry & Descriptive Stats

Enter data in a list
STAT โ†’ 1: Edit
Type values into L1 (or L2, L3โ€ฆ). Press ENTER after each.
1-Variable Statistics
STAT โ†’ CALC โ†’ 1: 1-Var Stats
Gives xฬ„, ฮฃx, Sx, ฯƒx, n, min, Q1, Med, Q3, max
โœ“ Scroll down for the five-number summary
Clear a list
STAT โ†’ 1: Edit โ†’ highlight list name โ†’ CLEAR โ†’ ENTER
Do NOT press DEL โ€” that deletes the whole column.
Store a computation in a list
e.g. to compute differences: in the L3 header, type L1 โˆ’ L2 then ENTER.
Useful for paired t-tests.
๐Ÿ’ก Quick Tips for Exam Day