BookmarkSubscribeRSS Feed
🔒 This topic is solved and locked. Need further help from the community? Please sign in and ask a new question.
Sathish_jammy
Lapis Lazuli | Level 10

Dear Experts, 

 

I have a dataset containing 2 columns - Weight, Follow_weight

I need to find the pval value using ttest for those variables.

Weight column contains 120 values in each row, F_wt column contains only 78 rows

Just for a sample, I share the data (have) here.

data have;
input Wt F_wt;
cards;
56.8 59.2 
75.2 71.3
88.0 85.1
76.5 76.2
101
26.5

Does the below method will return correct pval?

 

ods select none;
ods output ttests=ttest
           statistics=tstats;
proc ttest data=have;
paired wt*f_wt;
run;

Don't use the above dataset for analysis, It's just for a visual.

 

 

1 ACCEPTED SOLUTION

Accepted Solutions
ed_sas_member
Meteorite | Level 14

Hi @Sathish_jammy 

 

If the Weight column contains 120 values in each row and F_wt column contains only 78 rows, I assume that their are missing values for F_wt.

In this case, if you want to perform a Paired Sample Means t-test, the syntax of your t-test is correct. The test will take into account only pairs (so it will exclude rows with missing values)  : it will calculate the difference between each pair of Wt and F-wt and then perform the test (-> p_value)

In your example : 6 rows, but only 4 pairs as 2 values are missing.

View solution in original post

2 REPLIES 2
ed_sas_member
Meteorite | Level 14

Hi @Sathish_jammy 

 

If the Weight column contains 120 values in each row and F_wt column contains only 78 rows, I assume that their are missing values for F_wt.

In this case, if you want to perform a Paired Sample Means t-test, the syntax of your t-test is correct. The test will take into account only pairs (so it will exclude rows with missing values)  : it will calculate the difference between each pair of Wt and F-wt and then perform the test (-> p_value)

In your example : 6 rows, but only 4 pairs as 2 values are missing.

ballardw
Super User

@Sathish_jammy wrote:

Dear Experts, 

 

I have a dataset containing 2 columns - Weight, Follow_weight

I need to find the pval value using ttest for those variables.

Weight column contains 120 values in each row, F_wt column contains only 78 rows

Just for a sample, I share the data (have) here.

data have;
input Wt F_wt;
cards;
56.8 59.2 
75.2 71.3
88.0 85.1
76.5 76.2
101
26.5

Does the below method will return correct pval?

 

ods select none;
ods output ttests=ttest
           statistics=tstats;
proc ttest data=have;
paired wt*f_wt;
run;

Don't use the above dataset for analysis, It's just for a visual.

 

 


For your example data likely not. The way your data step for the example data is set the value 26.5 is paired with 101. Is that intentional? If not then you may have intended the data step to be:

data have;
infile datalines truncover;
input Wt F_wt;
cards;
56.8 59.2 
75.2 71.3
88.0 85.1
76.5 76.2
101
26.5
;

Which results in values of WT with missing values for F_wt.

SAS INNOVATE 2024

Innovate_SAS_Blue.png

Registration is open! SAS is returning to Vegas for an AI and analytics experience like no other! Whether you're an executive, manager, end user or SAS partner, SAS Innovate is designed for everyone on your team. Register for just $495 by 12/31/2023.

If you are interested in speaking, there is still time to submit a session idea. More details are posted on the website. 

Register now!

What is Bayesian Analysis?

Learn the difference between classical and Bayesian statistical approaches and see a few PROC examples to perform Bayesian analysis in this video.

Find more tutorials on the SAS Users YouTube channel.

Get the $99 certification deal.jpg

 

 

Back in the Classroom!

Select SAS Training centers are offering in-person courses. View upcoming courses for:

View all other training opportunities.

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