Ch. 2
histogram
A common graphical presentation of quantitative data, no natural separation between rectangles
frequency distribution
A summary chart, showing how frequently each of the various scores in a set of data occurs
contingency table
A table used to classify sample observations according to two or more identifiable categories or classes.
frequency
How often a piece of data occurs.
relative frequency
Number of times an allele occurs in a gene pool compared with the number of times other alleles occur
ogive
a graph of the cumulative relative frequencies from a relative frequency distribution
values of a variable
a set of ranges within which the data fall
stem and leaf diagram
a simple way to see distribution details quantitative data
cell
gives the count for a combination of values of the two variables
cumulative relative frequencies
cumulative frequency of a class divided by the total number of observations
bar chart
displays the distribution of a categorical variable, showing the counts for each category next to each other for easy comparison
relative frequency table
displays the percentages that lie in each category rather than the counts
corresponding frequencies
frequencies with which data fall within each range
pie chart
is a commonly used graphical device for presenting relative frequency distributions for qualitative data
bar graph
is a graphical device for depicting qualitative data
frequency table
is a tabular summary of data showing the frequency of items in each of several non-overlapping classes
percent frequency
is the relative frequency multiplied by 100. distribution
continuous data
may take on any value in some interval
conditional distribution
restrict variables in a distribution to show the distribution for just those cases that satisfy a specified condition
relative frequency bar chart
shows a bar representing the percentage count of each category in a categorical variable
bars are separated
technique used to distance bars on graph
categorical data condition
the data are counts or percentages of individuals in categories
column percent
the proportion of each column contained in the cell of a frequency table
row percent
the proportion of each row contained in the cell of a frequency table
total percent
the proportion of the total contained in the cell of a frequency table
marginal distribution
the total count that occurs when the value of that variable is held constant
bar of fixed with
used to create bars on bar graph
