Considering Categorical Data (1.7)

To answer this question we examine the row proportions....

% Females looking for a spouse: 51 / 137 ~ 0.37 % Males looking for a spouse: 18 / 70 ~ 0.26

bar plot (def)

A bar plot is a common way to display a single categorical variable.

frequency bar plot (def)

A bar plot where proportions instead of frequencies are shown is called a relative frequency bar plot.

Contingency Tables (def)

A table that summarizes data for two categorical variables is called a contingency table. (data matrix) (2 variables = 1 variable for rows + 1 variable for columns)

Bar plot vs Histogram characteristics

Bar plots are used for displaying distributions of categorical variables The x-axis represents categories Histograms are used for numerical variables The x-axis in a histogram is a number line ; Histograms have bin width, looks similar to histogram but box plots have x axis that is numerical

Analyze the Pie Chart >>>

Can you tell which order encompasses the lowest percentage of mammal species?

(refer to pic >>>)

Does there appear to be a relationship between gender and whether the student is looking for a spouse in college?

(answer to previous ?)

Raw Count Proportion,% Two Variables

(answer to previous ?)

Total = 115

Hollow Histogram (pros & cons)

can look through it, shows trends, darker colors & density ; time consuming

numerical data characteristics

discrete or continuous - interval - ratio

categorical data characteristics

nominal binary (2 possibilities) (new)* ordinal

frequency tables...

show the count -- a table for a singular variable

relative frequency tables...

show the proportion or %

mosiac = ___ variable combined visual ; the wider the bar = ?

two ; more people can look without any numbers & reach conclusion

1 way table =

1 variable

Example >>>

115 Oxford Students were surveyed to determine which day of the week students seem to have the most tests. The following results were obtained: M -18, Tu - 24, W - 15, Th - 22, F - 36. Show a frequency and relative frequency table for the information.