topic Re: Calculate Percentage for 95 % CI in Statistical Procedures

Calculate Percentage for 95 % CI

vandhan — Fri, 21 Jul 2017 12:20:19 GMT

Hello There,

I have calculated using Proc Means procedure.

Now I wanted to Calculate Percentage for this CIs.

How would I compute percentage (%) for 95% CIs I am cluless seeing first time.

Please help.

TRT A TRT B

95% CI (x.xx, x.xx) (x.xx, x.xx)
CI[%] XX.X XX.X

Re: Calculate Percentage for 95 % CI

RW9 — Fri, 21 Jul 2017 12:25:14 GMT

You can do it in a number of ways, the simplest being:

From means:

http://support.sas.com/documentation/cdl/en/proc/61895/HTML/default/viewer.htm#a002473542.htm

Fro univariate:

http://support.sas.com/documentation/cdl/en/procstat/67528/HTML/default/viewer.htm#procstat_univariate_examples09.htm

Re: Calculate Percentage for 95 % CI

Rick_SAS — Fri, 21 Jul 2017 12:26:19 GMT

I don't understand your question. Could you provide an example? For example, what sort of output would you want for the following example?


data Have;
call streaminit(1);
do i = 1 to 20;
   Trt = "A";    x = rand("uniform");
   output;
end;
do i = 1 to 15;
   Trt = "B";    x = 0.5 + rand("uniform");
   output;
end;
drop i;
run;

proc means data=Have mean LCLM UCLM;
class Trt;
var x;
run;

Re: Calculate Percentage for 95 % CI

vandhan — Fri, 21 Jul 2017 12:28:12 GMT

Thanks for your reply on this.

I see it is giving just CIs. I would want calculate % Percentage for those CIs.

Re: Calculate Percentage for 95 % CI

PaigeMiller — Fri, 21 Jul 2017 12:40:55 GMT

@vandhan wrote:

Thanks for your reply on this.

I see it is giving just CIs. I would want calculate % Percentage for those CIs.

I'm afraid I don't understand the meaning of "% Percentage" in the context of confidence intervals. This is not a statistical phrase that I have ever seen.

Re: Calculate Percentage for 95 % CI

Rick_SAS — Fri, 21 Jul 2017 12:43:04 GMT

Maybe we are having a communication issue. You say "I would want calculate % Percentage for those CIs," but we don't know what that means.

A confidence interval is an interval estimate for a parameter. In 95% of random samples, the 95% CI will contain the true parameter for a population that satisfies the assumptions of the method.

Are you asking "how many data values are inside the 95% CI"? Statistically speaking, that is a question that doesn't provide any insight into the inference. It is an irrelevant question.

Re: Calculate Percentage for 95 % CI

vandhan — Fri, 21 Jul 2017 12:56:10 GMT

In my question there is a mock i given. i want second row to be calculated. First row CIs comes from lcm option in Mean Lower and Upper CIs.

Re: Calculate Percentage for 95 % CI

Rick_SAS — Fri, 21 Jul 2017 13:28:44 GMT

My previous post includes simulated data that has 35 observations. Please use that data to show what percentages you want to get for the second row.