iscamtwosamplet: Two Sample T-Test

In ISCAM: Companion to the Book "Investigating Statistical Concepts, Applications, and Methods"

Two Sample T-Test

Description

twosamplet calculates a two sample t-test and/or interval from summary data. It defaults to a hypothesized population mean difference of 0. You can optionally set an alternative hypothesis and confidence level for a two-sided confidence interval.

Usage

iscamtwosamplet(
  x1,
  sd1,
  n1,
  x2,
  sd2,
  n2,
  hypothesized = 0,
  alternative = NULL,
  conf.level = 0,
  verbose = TRUE
)

Arguments

x1	Observed mean for group 1.
sd1	Observed standard deviation for group 1.
n1	Sample size for group 1.
x2	Observed mean for group 2.
sd2	Observed standard deviation for group 2.
n2	Sample size for group 2.
hypothesized	Hypothesized difference in population means.
alternative	"less", "greater", or "two.sided"
conf.level	Confidence level.
verbose	Logical, defaults to TRUE. Set to FALSE to suppress messages iscamtwosamplet( x1 = 25, sd1 = 5, n1 = 40, x2 = 22, sd2 = 6, n2 = 45, alternative = "greater" ) iscamtwosamplet( x1 = 10, sd1 = 2, n1 = 50, x2 = 12, sd2 = 2.5, n2 = 50, alternative = "two.sided" ) iscamtwosamplet( x1 = 8, sd1 = 1.5, n1 = 30, x2 = 5, sd2 = 1.8, n2 = 33, alternative = "greater", hypothesized = 2 ) iscamtwosamplet( x1 = 15, sd1 = 3, n1 = 25, x2 = 12, sd2 = 3.5, n2 = 28, conf.level = 0.95 )

Value

The t value, p value, and confidence interval.

ISCAM documentation built on Feb. 12, 2026, 5:07 p.m.