data Flashcards
Dot plot
a graph that uses dots to show the frequency counts of a group of data. Dot plots are used for small sets of quantitative data. You can easily identify the mode, the shape or skew of the graph, and potential outliers on a dot plot.
Stem-and-leaf plot/stemplot
a plot that splits each data value into a “leaf” (usually the last digit) and a “stem” (the other digits). Stemplots are used for smaller sets of quantitative data. You can easily identify outliers, data clusters, or gaps on a stemplot
Normal distribution
graph with a bell-shaped curve, where the graph is symmetric and has no skew
Minimum
lowest value of the data set
Negative Skew/ Skewed left
distribution of data with a tail that pulls to the left, toward the smaller numbers. reflects a bunching of data at the upper end of the distribution.
Box-and-whisker plot/ Boxplot
A boxplot splits the data set into quartiles, where the middle 50% of the data forms the box and the lower 25% and upper 25% form the whiskers. Boxplots are used with larger sets of data. You can easily identify the median, the shape or skewness of the graph, and the range on a boxplot
Positive skew / Skewed right
distribution with a tail that pulls to the right, towards the larger numbers. reflects a bunching of data at the lower end of the distribution
1st quartile (Q1)
median of the lower half of the data set
Bar Graph
a visual representation of data which compares values in different categories
Pie chart
a graph in which a circle is divided into sectors that each represent a proportion of the whole. Pie charts are helpful when displaying the relative distribution of categories
Quartiles
divide a set of data into four equal parts, using 3 divisions
Standard deviation
An average of how far each data point is away from the mean. A higher standard deviation indicates higher variability in the data (the data are more spread out). The Greek symbol sigma (σ) is used to represent standard deviation
Double Bar graph
a visual representation of data which compares values in different categories and groups
Mean
a measure of center commonly known as the average; found by adding all of the numbers in a data set and dividing by the number of numbers (the n) in the data set
Interquartile range (IQR)
The difference between Q3 (median of the top half of the data) and Q1 (median of the bottom half of the data)
Quantitative data
data which is measured and usually expressed numerically
Range (stats)
The width of the data set.
Range = highest value - lowest value
Maximum
highest value of the data set
3rd quatiles (Q3)
median of the upper half of the data set
Cluster
a group of data points that are gathered around a particular value
Gap
an interval in a data set that does not contain data
Mode
the most frequent number in a data set; data sets can have zero or multiple modes
Line graph
a visual representation of data which shows change over time or in response to a manipulated variable
2nd quartile (Q2)
the middle number of the data when the data are written in order
Median
the middle value of a sorted dataset; the middle number of a set with an odd quantity of values, or, when there is an even number of values, the mean of the middle two numbers
Categorical data
data recorded as categories/groups
Example: color
Histogram
a visual representation of data which compares frequencies of different numeral intervals
Outlier
a data point either much larger than or much smaller than the other data points in the set
