equation in two variables. For example, x–y= 3, x+ 2y= 14,
4 x–9=– 5 y, etc. This is often written as ax+by+c= 0. If the equation
has the same criteria and three variables, it is called a linear equation in
three variables, and is often written as ax+by+cz+d= 0.linear sequenceSeeARITHMETIC SEQUENCE.
list method of specificationSeeROSTER METHOD OF SPECIFICATION.
literal equationAny EQUATIONthat contains letters, VARIABLEs, and
numbers. For example, 4x+ 2y=ax+y.
logarithmAn EXPONENTthat represents a number, based on a system that uses
a common base and its exponents to represent number values. For
example, in a base 10 system, 10,000 = 10^4. The exponent becomes
the log that represents the number, so 4 is the log of 10,000. This is
useful for dealing with very large numbers and the RATIOs between
them on a scale, such as the Richter scale.
logarithmic scaleA scale that spaces the DISTANCEs between quantities as
RATIOs, for example, the Richter scale, as opposed to the linear scale,
which spaces the distances equally between units.
lowest termsThe canceling of all COMMON FACTORs in both the NUMERATOR
and DENOMINATOR. For example, the FRACTION—^1525 is reduced to its
lowest terms of–^35 by canceling out the common FACTORof 5 in both
the numerator and the denominator. In finding the lowest terms, the
fraction is divided by the HIGHEST COMMON FACTOR.
See alsoSECTION IV CHARTS AND TABLES.
mathematical sentenceAny mathematical phrase that includes any of the
following symbols: <, ≤, >, ≥, =, ≠. For e xample, 3x+y≤15,
7<x< 12, –3 ×–3 = 9 are each a mathematical sentence. Any
mathematical sentence with an equals sign, such as –3 ×–3 = 9, is
specifically called an EQUATION.
matrix A rectangular chart of rows and columns, used to compare quantities
or data.
mean (average)The value obtained from the SUMof a SETof numbers,
divided by the amount of numbers in that set. For example, in the set
of 2, 5, 6, 8, 9, 15 the mean is obtained from the sum (45) divided by
the amount of numbers in the set (6), so the mean is 7.5.
medianThe middle value in an ordered SETof values. For example, in the set
of 8, 12, 19, 22, 35, the median is 19. In an even-numbered set, the
median is the AVERAGEof the middle two values. For example, in the
linear sequence – median GLOSSARY
linear sequence – median GLOSSARY
16
89
134
147
162median
Median