Mandelbrot set

Discovered much later than Julia sets, it is generated by taking the set of all functions f(Z)=Z^2+C, looking at all of the possible C points and their Julia sets, and assigning colors to the points based on whether the Julia set is connected or dust.

mean

The sum of a list of numbers, divided by the total number of numbers in the list. Also called arithmetic mean.

median

"Middle value" of a list. The smallest number such that at least half the numbers in the list are no greater than it. If the list has an odd number of entries, the median is the middle entry in the list after sorting the list into increasing order. If the list has an even number of entries, the median is equal to the sum of the two middle (after sorting) numbers divided by two. The median can be estimated from a histogram by finding the smallest number such that the area under the histogram to the left of that number is 50%.

mixed numbers

Numbers that have both whole numbers and decimals, such as 4.567.

mode

For lists, the mode is the most common (frequent) value. A list can have more than one mode. For histograms, a mode is a relative maximum ("bump").

modular arithmetic

A method for finding remainders where all the possible numbers (the numbers less than the divisor) are put in a circle, and then by counting around the circle the number of times of the number being divided, the remainder will be the final number landed on.

modulus

A unit of measure. For example, when measuring days, a modulus could be 24 for the number of hours in a day. 75 hours would be divided by 24 to give 3 remainder 3, or 3 days and 3 hours. See also modular arithmetic.

multimodal distribution

A distribution with more than one mode. The histogram of a multimodal distribution has more than one "bump".

multiples

The product of multiplying a number by a whole number. For example, multiples of 5 are 10, 15, 20, or any number that can be evenly divided by 5.

multiplication

The operation by which the product of two quantities is calculated. To multiply a number b by c is to add b to itself c times.

multiplication rule

The probability that events A and B both occur (i.e., that event A&B occurs), is equal to the conditional probability that A occurs given that B occurs, times the unconditional probability that B occurs: P(A & B)=P(A/B)*P(B).