Google New or returning user — sign in with Google for instant login, no password needed. Sign in with Google Maybe later
Quiz title : Data Step - by groups
Question 1 of 5


How many number of times the value of first_age will be set to 1 when the below code is run on the input data shown in screenshot?</p></p>

proc sort data=class out=sorted;

    by age;

run;

 

data groups;

    set sorted;

    by age;

    first_age=first.age;

run;