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Before the advent of the scientific pocket calculator, it was the most commonly used calculation tool in science and engineering. [3] The slide rule's ease of use, ready availability, and low cost caused its use to continue to grow through the 1950s and 1960s, even as desktop electronic computers were gradually introduced.
The median can be regarded as a fully truncated mean and is most robust. As with other trimmed estimators , the main advantage of the trimmed mean is robustness and higher efficiency for mixed distributions and heavy-tailed distribution (like the Cauchy distribution ), at the cost of lower efficiency for some other less heavily tailed ...
The median effective dose is the dose that produces a quantal effect (all or nothing) in 50% of the population that takes it (median referring to the 50% population base). [6] It is also sometimes abbreviated as the ED 50, meaning "effective dose for 50% of the population". The ED50 is commonly used as a measure of the reasonable expectancy of ...
Unlike the nonstandardized t distributions, the noncentral distributions are not symmetric (the median is not the same as the mode). The discrete Student's t distribution is defined by its probability mass function at r being proportional to: [ 11 ] ∏ j = 1 k 1 ( r + j + a ) 2 + b 2 r = … , − 1 , 0 , 1 , …
The mean for the morning class is 80 and the mean of the afternoon class is 90. The unweighted mean of the two means is 85. However, this does not account for the difference in number of students in each class (20 versus 30); hence the value of 85 does not reflect the average student grade (independent of class).
Median aerodynamic diameter (MAD) is one of two parameters influencing the deposition of inhaled particles, the other being the geometric standard deviation of the particle size distribution. The MAD is the value of aerodynamic diameter for which 50% of some quantity in a given aerosol is associated with particles smaller than the MAD, and 50% ...
During the 20th century the median center of U.S. population moved roughly 180 miles (290 km) southwest, from a location in Randolph County, Indiana to a location in Daviess County, Indiana. The majority of this southwest shift happened in the second half of the century, as the center shifted within a narrow circular band between 1900 and 1950 ...
CompStat is a management system created in April 1994 by Bill Bratton and Jack Maple, whom Bratton met while he was chief of the New York City Transit Police and later hired as the New York Police Department's top anti-crime specialist when he became Police Commissioner in 1993. [1]