Page 362 - Algebra 1

SOLUTION
Find the median, Q1, Q3, and IQR. Identify any outliers.
To find the median, calculate th_e mean of the two middle numbers.
24+26 =25 2
Q1: 22 Q3: 30 IQR: 8
Q1 -1.5(IQR)=22-1.5(8)=10 Q3 +1.5(IQR)=30+1.5(8)=42
47 is an outlier because it is greater than 42.
Make a box-and-whisker plot. The upper whisker will end at 32, and 47 will be represented by an asterisk.
Flight Speeds of Birds
15 20 25 30 35 40 45 50
Comparing Data Using a Box-and-Whisker Plot
The table shows the average number of rebounds per game for the Texan Runners during the 2006–07 season.
a. Identify any outliers. SOLUTION
Q1 - 1.5(IQR) = 2.05 - 1.5(1.85) = -0.725 Q3 + 1.5(IQR) = 3.9 + 1.5(1.85) = 6.675 10.6 is an outlier.
b. Use a graphing calculator to make a box- and-whisker plot with and without the outlier. Which plot represents the data better?
SOLUTION
The plot that identifies the outlier is better. There are no values between 4.7 and 10.6. A whisker makes it look like data is distributed throughout that range. Using a plot that identifies the outlier shows that most of the data is very close to Q3.
Example
4
Rebounds Per Game, 2006–07
B. Gracia
10.6
T. Chin
3.2
M. Barry
4.4
J. Carl
2.7
R. Iffla
2.1
B. Abena
2.7
J. Kunto
2.8
P. Herut
1.1
A. Carlos
4.7
C. Franca
3.4
P. Daniels
2.0
S. Roberts
1.1
Graphing Calculator Tip
For help with graphing box-and-whisker plots, see Graphing Calculator Lab 4 on page 343.
Lesson 54 347