BookmarkSubscribeRSS Feed
Miracle
Barite | Level 11

Hi everyone.

I'm wondering if anyone could shed some light on this.

I don't understand why the confidence interval of the least squares means I manually calculated as

(logconc LSMEAN) plus/minus (1.96*Standard Error) is different from that produced by SAS.

My code is as below. Your help is greatly appreciated!

proc glm data=out order=internal;

  by Intervention;

  class Sample;

  model logconc=Sample / solution;

  lsmeans Sample / cl pdiff tdiff stderr e om;

run;

quit;

3 REPLIES 3
PaigeMiller
Diamond | Level 26

There's no way we can answer your question.

We can't see your data, we can't see the calculations you did, and we can't see the SAS output.

--
Paige Miller
lvm
Rhodochrosite | Level 12 lvm
Rhodochrosite | Level 12

Paige is right. One obvious thing: "1.96" is the t value with a large number of denominator df (say, df >30). The critical t value will be larger for small df.

Miracle
Barite | Level 11

Thanks very much Paige and Ivm for your reply Smiley Happy

Yes, I did it wrong by multiplying by 1.96 :smileysilly:

sas-innovate-2024.png

Join us for SAS Innovate April 16-19 at the Aria in Las Vegas. Bring the team and save big with our group pricing for a limited time only.

Pre-conference courses and tutorials are filling up fast and are always a sellout. Register today to reserve your seat.

 

Register now!

What is ANOVA?

ANOVA, or Analysis Of Variance, is used to compare the averages or means of two or more populations to better understand how they differ. Watch this tutorial for more.

Find more tutorials on the SAS Users YouTube channel.

Discussion stats
  • 3 replies
  • 1745 views
  • 2 likes
  • 3 in conversation