dotplot
individual values shown as a dot above its location on a number line
- shows distribution of a quantitative variable
overall pattern
shape, center, spread
outlier
individual value that falls outside the overall pattern
describing a distribution of quantitative data
S- shape
O- outliers
C- center
S- spread
shape
skewed/symmetrical and mode
mode; modes
most frequent; major peaks
center
median or mean
mean
average
median
the middle value of a data set when numbers are arranged from least to greatest
spread
how much variability in the data, range
range
highest value minus smallest value
skewed right
right side of the graph with larger values is longer than the left
skewed left
left side of the graph is much longer than the right side
symmetric
the right and left sides of the graph are almost mirror images
unimodal
single peak
bimodal
two clear peaks
multimodal
multiple peaks
stemplot
separate each observation into a stem and a one-digit leaf; show distribution of a quantitative variable
split stems
stem repeated twice: first line leaf values of 0-4, second line leaf values of 5-9; ex:
0 | 0 1 2 3 4
0 | 5 6 7 8 9
back-to-back stemplot
compare two variables, share same stem, work out from center on both sides
histogram
plot the counts (frequencies) or percents (relative frequencies) of values in equal-width classes; shows distribution of a quantitative variable