📖 Glossary

500 money, math, and health terms explained in plain English — each with an example and a free calculator.

40 terms found in Math & Statistics. Clear filters

A

Absolute Value The absolute value of a number is its distance from zero on the number line, regardless of direction, so it…

C

Confidence Interval A confidence interval is a range of values, calculated from sample data, that is likely to contain the true… Correlation Correlation is a statistical measure of how strongly two variables move together. The correlation coefficient…

E

Exponent An exponent shows how many times a number, called the base, is multiplied by itself. In 2⁵, the base is 2… Exponential Growth Exponential growth is growth in which a quantity increases by the same percentage in each period, so the…

F

Fraction A fraction represents a part of a whole or a division of one number by another, written as a numerator over a…

G

Grade Point Average (GPA) Grade point average (GPA) is a weighted average of a student's grades, where each letter grade is converted… Greatest Common Factor (GCF) The greatest common factor (GCF) of two or more whole numbers is the largest number that divides all of them…

I

Improper Fraction An improper fraction is a fraction whose numerator is greater than or equal to its denominator, such as 7/4… Interquartile Range (IQR) The interquartile range (IQR) is the difference between the third quartile (Q3) and the first quartile (Q1)…

L

Least Common Multiple (LCM) The least common multiple (LCM) of two or more whole numbers is the smallest positive number that each of… Linear Regression Linear regression is a statistical method that fits a straight line through data to describe the relationship… Logarithm A logarithm answers the question: to what power must a base be raised to produce a given number? For example…

M

Margin of Error Margin of error is the amount by which a survey or poll result may differ from the true value in the whole… Mean (Average) The mean, or arithmetic average, is the sum of all values in a data set divided by the number of values. For… Median The median is the middle value of a data set once the values are sorted in order. With an odd number of… Mixed Number A mixed number combines a whole number and a proper fraction, such as 2 3/4, meaning 2 plus 3/4. To convert… Mode The mode is the value that appears most often in a data set. In 2, 3, 3, 5, 8 the mode is 3. A data set can…

N

Normal Distribution A normal distribution is a symmetric, bell-shaped probability distribution in which values cluster around the…

O

Outlier An outlier is a data point that is unusually far from the other values in a data set. Outliers can come from…

P

Percentage A percentage is a number expressed as a fraction of 100, written with the % symbol. 25% means 25 out of 100… Percentage Change Percentage change measures how much a value has increased or decreased relative to its original value… Percentage Point A percentage point is the unit for the arithmetic difference between two percentages. If a rate rises from 4%… Percentile A percentile indicates the value below which a given percentage of observations in a data set fall. Scoring… Prime Factorization Prime factorization is writing a whole number as a product of prime numbers. For example, 60 = 2 × 2 × 3 ×… Prime Number A prime number is a whole number greater than 1 whose only positive divisors are 1 and itself, such as 2, 3… Probability Probability is a measure of how likely an event is to happen, expressed as a number from 0 (impossible) to 1…

Q

Quartile Quartiles divide an ordered data set into four equal parts. The first quartile (Q1) is the 25th percentile…

R

Range (Statistics) In statistics, the range is the difference between the largest and smallest values in a data set: range =… Ratio A ratio compares two or more quantities, showing how many times one contains the other. It can be written as… Roman Numerals Roman numerals are a number system from ancient Rome that uses letters: I = 1, V = 5, X = 10, L = 50, C =…

S

Sample vs. Population In statistics, a population is the entire group of interest, while a sample is a subset of that group… Scientific Notation Scientific notation is a way of writing very large or very small numbers as a number between 1 and 10… Significant Figures Significant figures (sig figs) are the digits in a number that carry meaningful information about its… Square Root The square root of a number is a value that, when multiplied by itself, gives that number. The square root of… Standard Deviation Standard deviation measures how spread out the values in a data set are around their mean. A small standard… Standard Error The standard error of the mean measures how much a sample mean is expected to vary from the true population…

V

Variance Variance is the average of the squared differences between each value and the mean of a data set. It measures…

W

Weighted Average A weighted average is a mean in which some values count more than others, according to assigned weights. It…

Z

Z-Score A z-score, or standard score, shows how many standard deviations a value is from the mean. Z = (value −…
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Definitions are for general educational purposes only and are not financial, tax, legal, or medical advice.