The MIDRANGE (middle range) function returns a numeric value that is the arithmetic mean (average) of the values of the minimum
argument and the maximum argument. The type of this function is numeric.

- Argument-1 must be class numeric.

- The returned value is the arithmetic mean of the greatest argument-1 value and the least argument-1 value.
- The comparisons used to determine the greatest and least values are made according to the rules for relation conditions. See the topic Relation Condition in the chapter Procedure Division.
- Floating-point format is used for numeric non-integer results.