Displaying Quantitative Data Dot Plots Time Plots Stem and Leaf Plots Histograms Box Plots Remember to always describe these graphs using CUSS after you have graphed your data.

Dot Plots Most Useful - Small number of values - Want to see individual values - Want to see the shape of the distribution - You have a small number of groups you want to compare Let’s make a dot plot for the number of movies we saw this summer.

Time Plots - Type of dot plot - Plot data in order according to time Example: page 57.

Stem and Leaf Plots Most Useful - Relatively Small number of values - Want to see the shape of the distribution - You have two or more groups to compare Sometimes just called a stem plot stemleaf You always need a key with stem plot.

Example: page 67 #17

Suppose the grades on a test were Make a stem plot Make a stem plot with split stems 9H 9L 8H 8L 7H 7L 6H 6L 5H 5L

Back – to – back stem plots Used to compare data Page 70 # 35

Histograms Most Useful - large number of values - You don’t need to see individual values - Want to see the shape of the distribution - You have a small number of groups you want to compare Draw backs - Individuals working with the same data could get different graphs We will use our calculator to create histograms, we will not create by hand

Example 1: Number of pieces of mail received at a school office for 36 days

Example 2: The Degree of Reading Power (DRP) scores for 44 third grade students First let us divide the data into classes and make a frequency chart classfrequency In L1 enter the smallest number of the class (10, 20, etc) In L2 enter the frequency You will need the change the window for your graph: Xmin=10, Xmax=60, Xscl = 10

Example 3: page 66: #15