Wikipedia
In statistics, the mid-range or mid-extreme of a set of statistical data values is the arithmetic mean of the maximum and minimum values in a data set, defined as:
$$M=\frac{\max x + \min x}{2}.$$
The mid-range is the midpoint of the range; as such, it is a measure of central tendency.
The mid-range is rarely used in practical statistical analysis, as it lacks efficiency as an estimator for most distributions of interest, because it ignores all intermediate points, and lacks robustness, as outliers change it significantly. Indeed, it is one of the least efficient and least robust statistics. However, it finds some use in special cases: it is the maximally efficient estimator for the center of a uniform distribution, trimmed mid-ranges address robustness, and as an L-estimator, it is simple to understand and compute.
Usage examples of "mid-range".
Furthermore, the laws of dynamics dictate a high risk of triadic horns becoming wedged into mid-range objects, so that none of the three horns might actually penetrate the body of the opponent.
Programmable neurophysin synthesis is too big, the stakes are now high enough to tempt mid-range players into the field.
Heck, my dad has a bass boat that cost him more than twenty-five thousand bucks and it's a mid-range one!
The mid-range troops provided weapons and communications of a higher order than those produced on Sulewesi, but at a tenth the cost of outfits like the Slammers and the Brazilians.