dealing with data

[s_m]

data scores;
infile '/folders/myshortcuts/s2/scores.txt';
input gender$1. score1 score2 score3 score4;
avg=(score1+score2+score3+score4)/4;
run;

In scores.text I have given one missing value for score2 in one obsevation.For the same obsevation Value of avg is also coming as missing.Please refer the screenshot attached.

Please tell me why avg is not coming for this obsevation. 

[ChrisBrooks · Accepted solution]

The result of any mathematical operation on a missing value results in an answer of missing hence your result.

If you want the average of the non-missing values use the mean function detailed here http://support.sas.com/documentation/cdl/en/lefunctionsref/69762/HTML/default/viewer.htm#p0vl2htnkjk...

[s_m]

Thanks for your help.