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Unit 2 Vocabulary


an alternative word for mean

balancing point

the point on a number line where the data distribution is balanced


the bell shape that is created on a graph of a normal distribution


the act of favoring one outcome over another


A special type of diagram showing Quartiles 1, 2 and 3 (where the data can be split into quarters) in a box, with lines extending to the lowest and highest values


the possibility that something will happen

compound probabilities

AND/OR probabilities; the likeliness of two independent events occurring


the act of departing from an established course or accepted standard

Empirical Rule

in a normal data set, virtually every piece of data will fall within three standard deviations of the mean


a set of possible outcomes resulting from a particular experiment

first quartile (Q1)

a number for which 25% of the data is less than that number

five-number summary

a set of numbers that provides information about a dataset; consist of minimum, first quartile, median, third quartile, and maximum


if one event doesn't affect the outcome of another event

interquartile range (IQR)

the range from Quartile 1 to Quartile 3


the largest value


a calculated "central" value of a set of numbers, where you add the numbers and divide by how many there are

mean of absolute deviations (MAD)

the average distance between each data value and the mean

measures of central tendency (or center)

a central or typical value for a probability distribution

measures of variability (or spread)

how far away the data points tend to fall from the center


the middle value in a group of ordered observations


to come together or combine


the smallest value


a way of representing real world situations so that predictions can be made

normal curve

curve or the graph is the common type of distribution for a variable

normal distribution

an arrangement of a data set in which most values cluster in the middle of the range


parts per 100; for each hundred; a fraction whose denominator (bottom) is 100


how likely it is that some event will occur


when two ratios (or fractions) are equal


a term that can be used in place of percentiles because they represent a quantity of data that is lower than that value


the values that divide a list of numbers into quarters


happening by chance; not able to be predicted


the largest value minus the smallest value


an opposing argument or debate


the form in which data is stored, processed, and transmitted

sample proportion

the fraction of samples which were successes


rearrange so as to occupy different random positions or to be in a different random order


a way of creating random events that are close to real-life situations without actually doing them

standard deviation (SD)

a measure of how spread out numbers are; the square root of the variance

standardized score

another name for z-score


a set of which all the variables are contained in another set.

third quartile (Q3)

a number for which 75% of the data is less than that number


“mean” or “average”; expected values

with replacement

when a population element can be selected more than one time

without replacement

when a population element can be selected only one time


tells us how many standard deviations away from the mean an observation is