Name _________________________________
Data Distributions with Outliers
Measures of Center
Plot F
WITH the outlier
Median:______
Mean:
Plot F
WITHOUT the outlier
Median:______
2.6
Mean:
2.2
Which measure of center is affected more when the outlier is removed?
Which measure of center provides a more accurate “center” when outliers are present?
Measures of Spread
Plot F
WITH the outlier
Plot F
WITHOUT the outlier
Range: ______
Range: ______
IQR: ______
IQR: ______
Describe what happened to the measures of spread when the outlier is removed.
Which measure of spread is more affected by an outlier?
Property of Cy-Fair ISD Middle School Math Dept.
Analyzing Center, Shape, and Spread Independent Practice
1.
Name _________________________________
The dot plot shows the number of cars sold at a car dealership each week during the first half
of the year.
Cars Sold
a.
Which best describes the shape of the data?
A.
B.
C.
Symmetrical
Asymmetrical
The data has no shape
b.
Which measure of center (mean or median) is a better representation of the data? _____________
Why?
c.
The owner decides to remove the outlier from the data set. How does this affect the range?
2.
The monthly average temperatures for a year in Ontario, Canada are represented in the stem and
leaf plot shown below.
Normal Monthly
Temperatures for Ontario
Stem
Leaf
1
2
3
4
9
5
0 7 8 9
6
1 7 7 8
0 8 9
3 | 7 = 37°F
Which measure of center better represents the data?
A.
B.
C.
D.
Mean, because 19 is an outlier.
Range, because 19 is not an outlier.
Median, because 19 is an outlier.
The mean and median, because 19 is an outlier.
Property of Cy-Fair ISD Middle School Math Dept.
Name _________________________________
3.
The stem and leaf plot shows the game points earned for the Cy-Fair Middle
School basketball team during each game of the season.
Which statement is best supported by the information in the plot?
A. The team scored fewer than 200 points all season.
B. The median of the data is 30.
C. Cy-Fair Middle School played 15 games.
D. The team scored more than 30 points in half of the games.
4.
The students in Mr. Rogers’ homeroom class wanted to see how many pets were in each household
for students in the class. They organized their collected data on the dot plot shown below.
Household Pets
Which statement about the dot plot is not supported by the data?
A. The data peaks at 1.
B. The mean and the median of the data are the same.
C. The data distribution is asymmetrical.
D. The data spreads from 0 to 8.
5.
A nurse measured a patient’s heart rate at different times over several days and created the dot
plot below.
Heart Rate
Which measures of spread and measures of center can you find from a dot plot?
A.
B.
C.
D.
E.
Range
IQR
Median
Mean
All of the above
Property of Cy-Fair ISD Middle School Math Dept.
Name _________________________________
6.
A teenager kept a chart of how much money he earned tutoring math during 8 weeks over the
summer. The chart is provided below.
Money Earned from
Tutoring
$45
$30
$38
$44
$30
$45
$35
$38
What was the average amount of money the teenager earned each week
tutoring?
7. Use the dot plot below to answer the following question.
Which statement best supports the data represented in the dot plot?
A. The distribution of the data is asymmetrical, so the mean and the median are likely the same
value.
B. The distribution of the data is asymmetrical, so the mean and the median are likely different
values.
C. The distribution of the data is symmetrical, so the mean and the median are likely the same value.
D. The distribution of the data is symmetrical, so the mean and the median are likely different values.
8.
Look at the dot plot below.
Ages of People at Camp
Choose true or false for each statement as it relates to the dot plot.
_______ a.
When the outlier is removed, the range will increase.
_______ b.
The outlier will raise the value of the mean more than the value of the median.
_______ c.
The median and mean are both 13.
Property of Cy-Fair ISD Middle School Math Dept.