n.indep.t.test.neq {samplesize}R Documentation

Sample size for independent Student's t-test with unequal group size

Description

Function computes sample size for independent Student's t-test with unequal group size

Usage

n.indep.t.test.neq(power = 0.8, alpha = 0.95, mean.diff = 0.8, sd.est = 0.83, k = 0.5)

Arguments

power required power 1-beta
alpha required Level I-error 1-alpha
mean.diff required minimum difference between group means
sd.est standard deviation in groups
k n_2=n_1*k

Details

n_1= size group 1, n_2= size group 2, N=n_1+n_2

Value

N total sample size
n.1 sample size group 1
n.2 sample size group 2

Author(s)

Ralph Scherer

References

Bock J., Bestimmung des Stichprobenumfangs fuer biologische Experimente und kontrollierte klinische Studien. Oldenbourg 1998

See Also

n.indep.t.test.eq(), n.paired.t.test(), n.welch.test()

Examples

n.indep.t.test.neq(power = 0.8, alpha = 0.95, mean.diff = 0.8, sd.est = 0.83, k = 0.5)

[Package samplesize version 0.1-6 Index]