Hi,
I am trying to calculate confidence intervals using ci.numeric from epicalc
package. If I generate a normal set of data and find the 99% and 95% CI, they
seem too narrow to me. Am I doing something wrong?? The IQR goes from -0.62 to
0.62, so I thought the CI limits should be more extreme than these values.
x<- rnorm(200,0,1)
ci.numeric(x=mean(x),n=200,sds=sd(x),alpha=0.05)
n mean sd se lower95ci upper95ci
1 200 -0.07129813 1.015668 0.07181859 -0.2129213 0.0703250
ci.numeric(x=mean(x),n=200,sds=sd(x),alpha=0.01)
n mean sd se lower99ci upper99ci
200 -0.07129813 1.015668 0.07181859 -0.2580811 0.1154848
quantile(x)
0% 25% 50% 75% 100%
-3.23354673 -0.61926758 -0.06672757 0.62000897 2.43763696
Thanks,
D.
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