Transcript Graphical Displays of Quantitative Data

GRAPHICAL DISPLAYS OF
QUANTITATIVE DATA
Ch. 4 Day 1
AP Statistics
EQ: How do we display
quantitative data?
Requirements for ALL Graphs
Title for the graph
 Title for each axis
 Clearly label or number axis
 Appropriate scale for the data set
 Legend for the graph (when needed)

Histograms
Provide an easy to understand summary of the
Quantitative
distribution of a ____________________
variable
Use bins which are equal width piles
Count the number of values that fall into each
bin
Histogram Examples
Histogram Quick Practice
Make a Histogram for the number of wins for each Major League
Baseball team in 1997:
98
78
65
84
96
68
101
79
79
67
92
76
88
76 86 80
90 84 77
88 78 68
73 68 90
83
Histogram Quick Practice
Interval
65-70
Frequency
5
1
7
4
3
3
2
1
Stem and Leaf Plots
Shows individual data points
Use for ______________
Quantitative variables
Why split stems? What is a back to back
stem and leaf plot?
Stem and Leaf Plot Examples
Dotplot
Places a dot along an axis for each
case in the data
 Shows all data values
 Use for ________________
variables
Quantitative
 What does a dot actually represent?

Dotplot Examples
Describing Distributions

Center (midrange/mean/median)

Unusual Features (gaps/clusters/outliers)

Shape (uniform, symmetric, skewed, uni-bi-multi-modal)

Spread (range, iqr, quartiles, standard deviation)
Describing Distributions

For Tonight’s HW: Focus on Shape
Unimodal
Bimodal
Multimodal
Describing Distributions

For Tonight’s HW: Focus on Shape
Symmetric Skewed Right Skewed Left
Describing Distributions

For Tonight’s HW: Focus on Shape
Uniform
PULSE RATE ACTIVITY
1.
2.
3.
4.
5.
Count your number of pulse beats in one
minute. (only do 10 seconds and multiply
by 6 or do 15 seconds and multiply by 4)
Repeat this three times, recording each
trial.
Find your average individual pulse rate.
Record your average pulse rate in the
class chart.
Find the average pulse rate for the males
and females.
Pulse Rate Data Histogram

Put the pulse rate data into a list
 STAT
then #1 EDIT
 Put all the pulse rates into L1
 1-Variable Stats (find the mean 𝑥)
To get to 1-variable statsStat-> Calc -> #1 and select L1
Pulse Rate Data Histogram

Graph a histogram
 STAT
PLOT then enter for Plot 1
 Turn Plot 1 on, choose the histogram graph, and
L1 for your data
 Hit graph (check y= before you graph!!!)
 Can’t
see your graph? Push Zoom #9
 Now let’s reset the bins to sensible values
Pulse Rate Data Histogram
Make a dotplot for the class
pulse rate data.
Make a stem and leaf plot
for the pulse rate data.
Male
Female
Make a back to back stem and leaf
plot for the pulse rate data.
5
6
7
8
Compare the two stem plots.
What do they show?
How are they alike?
How are they different?
Homework (Ch.4 Day1) (due Thurs)
p.72 #5, 6, 7, 10, 31, 37, 41