 Central tendency describes the middle or a typical value of the data set and is measured using the mean, median, and mode.
 Variability describes how spread out the data is.
 Quartiles divide a data set into four equal parts. The third quartile minus the first quartile is the range for the middle half of the data.
 A boxandwhisker plot shows the distribution of data. The middle half of the data is represented by a box with a vertical line at the median. the lower first and upper fourth are represented by whiskers that extend to the smallest and largest values.
Example:
Draw a boxandwhisker plot for the table below, that summarizes a veterinaian's record for kitten litters born in a given year.
Litter Size  2  3  4  5  6 
Number of Litters  1  6  8  11  1 
 Order the data and find the smallest value, first quartile, median, third quartile and largest value.
2 3 3 3 3 3 3 4 4 4 4 4 4  4  4 5 5 5 5 5 5 5 5 5 5 5 6 
Lower half   Upper half 
2 3 3 3 3 3 3 4 4 4 4 4 4  4  4 5 5 5 5 5 5 5 5 5 5 5 6 
First quartile  Second quartile  Third quartile 
median of lower half:3  Median:4  median of upper half:5 
smallest value: 2
first quartile: 3
median: 4
third quartile: 5
largest value: 6
 Draw a number line and plot above each value from step 1
 Draw the box and whiskers.
Directions: Answer the following questions. Also write at least 5 examples of your own.
