Keskiväli

Keskiväli is a Finnish term that commonly denotes a midpoint or middle position between two values. Depending on the context, it can refer to the geometric midpoint of a line segment, the midpoint of an interval, or a central value between two bounds. The concept is widely used in mathematics, geometry, surveying, and data analysis to describe a position or value that lies exactly in the middle.

In geometry, the keskiväli (midpoint) of a segment AB is the point M on AB such that AM = MB. In Cartesian coordinates, if A = (x1, y1) and B = (x2, y2), the midpoint M is ((x1 + x2)/2, (y1 + y2)/2). The midpoint divides the segment into two congruent segments.

For a closed interval [a, b], the keskiväli is the point (a + b)/2. In data analysis, the term may also refer to the mid-range, which is the average of the minimum and maximum values: (min + max)/2. This mid-range is a simple measure of central tendency that differs from the arithmetic mean (keskiarvo).

In practical use, keskiväli appears in tasks such as locating a central point for a construction, choosing a starting point in algorithms, and determining a balanced value between two constraints. It is a fundamental and widely applicable idea that helps quantify centrality or balance between two opposing ends.