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# Math Symbols

The "math" contained within this blog ranges from the purely mathematical equation (e.g., takt time, average) to metrics (e.g., inventory turns, order fill) to pseudo-mathematical (e.g., change management, waste elimination effectiveness) to concept introduction (e.g., hypothesis tests) to data and math integrity considerations (e.g., gauge repeatability and reproducibility, measurement system validation). So, the reader is bound to run into formulas, symbols, and mathematical definitions.

We try to keep things as simple as possible. Nevertheless, the following table of mathematical symbols may serve as a handy reference.

 Category Symbol Name Definition Example Basic Math = equals sign equality 7 = 4+3 > strict inequality greater than 7>6 < strict inequality less than 7<8 ≥ inequality greater than or equal to 7≥6 ≤ inequality less than or equal to 7≤8 ( ) parentheses calculate expression inside first 3x(4+1) = 15 [] brackets calculate expression inside first [(3+2)x(2+5)]=35 + plus sign addition 3+2=5 - minus sign subtraction 5-2=3 x times sign multiplication 3x5=15 / division slash division 8/2=4 ¯ horizontal line division/fraction ab power exponent 32=9 √ square root √9=±3 Algebra { } braces set floor brackets rounds number to lower integer  ceiling brackets rounds number to upper integer nearest integer rounds positive number to nearest integer |x| single vertical bar absolute value |-3|=3 (a,b) open interval ∑ sigma summation – sum of all values in a range or series Probability and statistics P(A) probability function probability of event A P(A)=0.7 P(A∩B) probability of events intersection probability of events A and B P(A∩B)=0.7 P(AUB) probability of events union probability of events A or B P(AUB)=0.7 P(A|B) conditional probability probability of event A given event B occurred P(A|B)=0.5 overbar or bar sample average 