Statistics definitions

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Terms in this set (...)

Data
A collection in a context.
Population
A set of individuals that we wish to describe and/or make predictions about.
Individual
Member of a population
Variable
Characteristics recorded about each individual in a data set.
Categorical variable
A variable that records qualities or characteristics of an individual such as gender or eye color.
Quantitative variable
Variable that measures a characteristic of an individual such as height, weight, or age.
Center
What is the most typical value.
Mode
The value that occurs the most.
Spread
How much do values typically vary from the center.
Range
The difference between the lowest and the highest values.
Outlier
Data value that doe not fit in the overall pattern.
Shape
Mound shaped and symmetrical, uniform, skewed left, and skewed right.
Sample
A set of data collected and/ or selected from a statistical population by a defined procedure.
Frequency
The number of times the event occurred in an experiment or study.
Frequency table
A table that shows the number of times a particular value is used as a data point.
Interval
Scales are numeric scales in which we know not only the order, but also the exact differences between the values.
Mean
Adding up the values and then dividing by the number of values.
Median
The middle value or the average of the middle of two values when the data is arranged in numerical order.
5 number summary
Minimum, Q1, median, Q3, and maximum.
IQR
Q1-Q3 the spread of middle 50% of data.(not sensitive to outliers.
Deviation
The amount that a single data value differs from the mean.
Standard deviation
Measure of how spread out numbers are.
Mean absolute deviation
The average distance between each data value and the mean.
First quartile
The middle lower half of the data. 25% of data is below Q1.
Third quartile
The middle upper half of the data. 25% of data is above Q3.
Two way table
Shows relationships between two categorical variables.
Joint frequencies
Represent the body of the table.
Marginal frequencies
Represents the total row and total column.
Sample size
The total number of individuals surveyed.
Residual
The difference between the observed value of the dependent variable and the predicted value.
Residual plot
A graph that shows the difference between the actual data. (What is provided through a table or graph) and the predicted data. (what the model says should happen).
Correlation
Measures a relationship between two variables.
Causation
One evet is the result of the occurrence of the other event.
Skew
To go in One Direction or the other.
Line of best fit
A straight line drawn through the center of a group of data points plotted on a scatterplot.
Bivariate statistics
Analyzing two variables to find the relationship between them.
Univariate statistics
Involves only one variable.