Can anyone explain why output from proc surveymeans can result in a ratio, when added to the confidence interval, exceeds 100% ? i.e., 97.0±10.8=107.8
Ratio=0.970
Standard Error=0.055
Confidence Interval=(1.96)*(Standard Error)=1.96*0.055=0.108
Code:
proc surveymeans data=la ratio nobs;
by race_eth;
var d24u
strata frame;
cluster sridnum;
weight weight;
ratio d24u students;
ods output ratio=laoutput;
run;
Log:
NOTE: The BY statement provides completely separate analyses of the BY groups. It does not provide a statistically valid subpopulation or domain analysis, where the total number of units in the subpopulation is not known with certainty. If you want a domain analysis, you should use the DOMAIN statement.
NOTE: Only one cluster in a stratum for variable(s) d24u, students. The estimate of variance for d24u, students will omit this stratum.
Only one cluster in a stratum for ratio(s) d24u/students. The estimate of variance for d24u/students, will omit this stratum.
NOTE: The above message was for the following by-group:
race_eth=Bl
Thanks.