median(redirected from 50th percentile)
Also found in: Dictionary, Thesaurus, Medical, Legal, Financial, Wikipedia.
median.1 In statistics, a type of averageaverage,
number used to represent or characterize a group of numbers. The most common type of average is the arithmetic mean. See median; mode.
..... Click the link for more information. . In a group of numbers as many numbers of the group are larger than the median as are smaller. In the group 4, 5, 6, 9, 13, 14, 19, the median is 9, three numbers being larger and three smaller. When there is an even number of numerals in the group, the median is usually defined as the number halfway between the middle pair. 2 In geometry, the line segment connecting any vertex of a triangle to the midpoint of the opposite side; the three medians of a triangle intersect in a single point, called the median point, or centroid. The median of a trapezoid is the line segment connecting the midpoints of the nonparalled opposite sides.
mediansee MEASURES OF CENTRAL TENDENCY.
in geometry, the line segment joining a vertex of a triangle to the midpoint of the opposite side. The three medians of a triangle are concurrent. Their common point is called the centroid of the triangle. The centroid of a triangle cut out of material of uniform density is the center of gravity. It is also the center of gravity of a system of three equal masses situated at the vertices of the triangle. The medians of a triangle divide one another in the ratio 2:1 reckoning from the vertex to the base.
in probability theory, one of the characteristics of the distribution of values of a random variable. For a random variable X with continuous distribution function F(x), the median m is defined as the root of the equation
The random variable X assumes values larger than m with probability ½ and values smaller than m with the same probability.
In mathematical statistics, the median of an ordered sequence of n quantities x1 ≤ x2 ≤ • • • ≤ xn is either xk, if n is odd and equal to 2k + 1, or (xk + xk+1)/2, if n is even and equal to 2k. As an estimate of the median for independent observations of a random variable X, we take the median of the ordered sequence constructed from the results of the observations.