Chapter II - Graphical Methods Flashcards
To study and memorize the concepts brought forth in Chapter II
Graphical Methods
gives us a picture of the data collected. For QN data, we also get an idea for the shape and distribution of the data
Bar Graph
bar length depends on relative frequencies of the categories. QL
Pie Chart
“slices” of the pie determined by relative frequencies. QL
Bar Graph
groups similar data together and draws bars
Stem and Leaf Display
data values are broken into “stems” and “leaves”
Symmetric Distribution
two halves of the distribution are “halves” or symmetrical
Skewed
one “tail” of the distribution tapers farther than the other. The end that tapers down is the direction in which the graph is skewed. (left skews are much less common)
Frequency Distribution
tabular summary of data showing the number (fre- quency) of items in each of several nonoverlapping classes
Relative Frequency
Frequency/n
Percent Frequency
Relative Frequency X 100
Approximate Class Width
(largest data value - smallest data value)/# classes
Cumulative Frequency Distribution
variation of the frequency distribution that provides another tabular summary of quantitative data. shows the number of data items with values less than or equal to the upper class limit of each class
Ogive
graph of a cumulative distribution. shows data values on the horizontal axis and either the cumulative frequencies, the cumulative relative frequencies, or the cu- mulative percent frequencies on the vertical axis
Crosstabulation
tabular summary of data for two variables
Chebyshev Rule
89% of measurements fall within 3 standard deviations of the mean. 75% within 2 standard deviations of the mean.
