You can use PROC MEANS to calculate summary statistics for variables in SAS.
By default, PROC MEANS does not display the interquartile range (IQR) as one of the summary statistics but you can use the QRANGE statement to include the IQR in the output:
proc means data=my_data N Mean QRANGE Std Min Max; var points; run;
This particular example calculates the total number of observations, mean, interquartile range, standard deviation, minimum and maximum value for a variable called points.
The following example shows how to use this syntax in practice.
Example: Display IQR in PROC MEANS in SAS
Suppose we have the following dataset in SAS that contains information about various basketball players:
/*create dataset*/ data my_data; input team $ points assists; datalines; A 10 2 A 17 5 A 17 6 A 18 3 A 15 0 B 10 2 B 14 5 B 13 4 B 29 0 B 25 2 C 12 1 C 30 1 C 34 3 C 12 4 C 11 7 ; run; /*view dataset*/ proc print data=my_data;
Suppose we use PROC MEANS to calculate summary statistics for the points variable in the dataset:
/*calculate summary statistics for points variable*/ proc means data=my_data; var points; run;
By default, PROC MEANS calculates the following descriptive statistics:
- N: The total number of observations
- Mean: The mean value of points
- Std Dev: The standard deviation of points
- Minimum: The minimum value of points
- Maximum: The maximum value of points
Notice that the IQR is not included in the output.
We can use the following syntax to include the IQR in the output:
/*calculate summary statistics for points and include IQR*/ proc means data=my_data N Mean QRANGE Std Min Max; var points; run;
Notice that the output now includes the interquartile range value for the points variable.
We can see that the IQR for the points variable turns out to be 13.
Recall that the IQR represents the difference between the 75th percentile and the 25th percentile for a given variable.
If you’d like to see the values for these percentiles, you can include P25 and P75 in the PROC MEANS procedure:
/*calculate summary statistics for points and include IQR*/ proc means data=my_data N Mean P25 P75 QRANGE Std Min Max; var points; run;
The output now includes the 25th percentile, the 75th percentile, and the interquartile range for the points variable.
The following tutorials explain how to perform other common tasks in SAS:
How to Calculate Descriptive Statistics in SAS
How to Create Frequency Tables in SAS
How to Calculate Percentiles in SAS
How to Create Pivot Tables in SAS