ztest: Test for the difference of two groups' means

In sasLM: 'SAS' Linear Model

Test for the difference of two groups' means

Description

This is similar to two groups t-test, but using standard normal (Z) distribution.

Usage

  ztest(m1, s1, n1, m0, s0, n0, conf.level=0.95, nullHypo=0)

Arguments

m1	mean of the first (test, active, experimental) group
s1	known standard deviation of the first group
n1	sample size of the first group
m0	mean of the second (reference, control, placebo) group
s0	known standard deviationo of the second group
n0	sample size of the second group
conf.level	confidence level
nullHypo	value for the difference of means under null hypothesis

Details

Use this only for known standard deviations (or variances) or very large sample sizes per group.

Value

The output format is very similar to t.test

Author(s)

Kyun-Seop Bae [e-mail]

See Also

mtest, tmtest, TTEST

Examples

  ztest(5.4, 10.5, 3529, 5.1, 8.9, 5190) # NEJM 388;15 p1386

sasLM documentation built on Nov. 19, 2023, 5:12 p.m.