ci.median {statpsych} | R Documentation |
Confidence interval for a median
Description
Computes a distribution-free confidence interval for a population median. Tied scores are assumed to be rare.
Usage
ci.median(alpha, y)
Arguments
alpha |
alpha level for 1-alpha confidence |
y |
vector of scores |
Value
Returns a 1-row matrix. The columns are:
Estimate - estimated median
SE - standard error
LL - lower limit of the confidence interval
UL - upper limit of the confidence interval
References
Snedecor GW, Cochran WG (1989). Statistical Methods, 8th edition. ISU University Pres, Ames, Iowa.
Examples
y <- c(30.2, 20.4, 15.1, 10.2, 10.5, 60.8, 20.8, 25.0, 20.7, 30.9, 10.8, 5.1,
50.9, 40.0, 20.9, 10.8, 0, 20.5, 50.8)
ci.median(.05, y)
# Should return:
# Estimate SE LL UL
# 20.7 4.292277 10.8 30.9
[Package statpsych version 1.8.0 Index]