docs/ratio.mean.is.md

In cwendorf/dgb: DGB

Ratio of Means from Two (Independent) Samples

ci.ratio.mean.is.data

Compute confidence interval for a ratio of population means of ratio-scale measurements in a 2-group design. Equality of variances is not assumed.

Arguments: - alpha: alpha level for 1-alpha confidence - y1 vector of scores for group 1 - y2: vector of scores for group 2

Values: - means, mean ratio, lower limit, upper limit

alpha = .05
group2 = c(32, 39, 26, 35, 43, 27, 40, 37, 34, 29, 49, 42, 40)
group1 = c(36, 44, 47, 42, 49, 39, 46, 31, 33, 48)
ci.ratio.mean.is.data(alpha, group1, group2)

##      Mean1    Mean2 Mean1/Mean2        LL       UL
## [1,]  41.5 36.38462    1.140592 0.9897482 1.314425

size.ci.ratio.mean.is

Computes sample size required to estimate a ratio of population means with desired precision in a 2-group design.

Arguments: - alpha: alpha level for 1-alpha confidence - var: planning value of average within-group DV variance - m1: planning value of mean for group 1 - m2: planning value of mean for group 2 - r: desired upper to lower confidence interval endpoint ratio

Values: - required sample size per group

alpha = .05
var = .4
m1 = 3.5
m2 = 3.1
r = 1.2
size.ci.ratio.mean.is(alpha, var, m1, m2, r)

## [1] 70

cwendorf/dgb documentation built on May 3, 2022, 9:35 p.m.