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# Stats without TearsInferential Statistics: Basic Cases

Updated 29 Dec 2014

Summary: This table organizes procedures for basic inferential statistics into a chart of Cases. (The Case numbers are useful for reference, although they are not standard statistics terminology.) All links are live in the online version of this page.

See also:
Case Number
and Description
Pop.
Param.
TI-83/84/89 Procedures
(CI=conf int, HT=hypothesis test, SS=sample size)
All require random sample or randomization, and 10n ≤ N; additional requirements are noted in each case.
NUMERIC DATA — INFERENCES ABOUT MEANS
1One pop. mean, unknown σ μ Required: n ≥ about 30 or normal with no outliers.
CI: `TInterval`; HT: `T-Test`
SS: MATH200A part 5
3Mean difference for paired data μd Required: n ≥ about 30, or differences are normal with no outliers.
CI: `TInterval` using the differences; HT: `T-Test` using the differences
4Difference of 2 indep. pop. means, unpaired data μ1, μ2 or
μ1−μ2
Required: in each sample, n ≥ about 30 or normal with no outliers.
CI: `2-SampTInt`; HT: `2-SampTTest`
YES/NO COUNTS — INFERENCES ABOUT PROPORTIONS
2One pop. proportion p CI: `1-PropZInt`; requires ≥ 10 successes and ≥ 10 failures in sample.
HT: `1-PropZTest`; requires expected successes npo ≥ 10 and expected failures nnpo ≥ 10.
HT w/ small samples: MATH200A part 3 or `binomcdf`
SS: MATH200A part 5
5Difference of 2 pop. proportions p1, p2
p1p2
CI: `2-PropZInt`; each sample requires ≥ 10 successes and ≥ 10 failures.
HT: `2-PropZTest`; requires same as CI. If that’s not met, use pooled to test that n1, n1n1, n2, n2n2 are all ≥ 10.
SS: MATH200A part 5
CATEGORY COUNTS — INFERENCES ABOUT MODELS
6Goodness of fit (GOF) or multinomial none CI: undefined; HT: MATH200A part 6
TI-89 HT: `Chi2 GOF` or How to Test Goodness of Fit on TI-89
Required: every expected value ≥ about 5.
7Independence or homogeneity
(in 2-way table)
none CI: undefined; HT: `χ²-Test` or MATH200A part 7
TI-89 HT: `Chi2 2-way`
Required: every expected value ≥ about 5.

## What’s New?

• 29 Dec 2014: Move requirements for numeric data and category counts from the section heads to the individual cases. (Requirements for yes/no counts were already that way.)
• (intervening changes suppressed)
• 10 Nov 2007: New document, inspired by Dabes and Janik [see “Sources Used” at end of book].
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