SKILL: CALCULATING THE MEAN
OF A DATA SET
MATH TUTORIAL
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for more help finding
the mean.
Comparing Mountain
Heights
How do the tallest mountains in the United States
compare with the tallest
mountains in the world? The
table shows the heights of
the five tallest mountains
in the world. All five are
in Asia.
Mountain
Height (meters)
Everest
8850
K2
8611
Kanchenjunga
8586
Lhotse
8516
Makalu
8463
To describe data, you can find their average, or mean. The mean
of a data set is the sum of the values divided by the number of values.
Example
To find the mean height of the five tallest mountains in the
world, first add the heights.
8,850
Then divide by 5, the
8,611
number of mountains.
8,586
43,026
= 8605.2
5
8,516
Round your result to a
8,463
whole number.
43,026
ANSWER The mean height of the five tallest mountains is
8605 meters.
Answer the following questions.
Mountain
Height (meters)
McKinley
6194
St. Elias
5489
Foraker
5304
Bona
5029
Blackburn
4996
Mount McKinley, Alaska,
is the tallest mountain in
North America.
1. The table to the left shows the heights of the five tallest mountains in the United States. All five are in Alaska. Find the mean
of the data.
2. What is the difference between the mean height of the three
tallest mountains in the world and the mean height of the three
tallest mountains in the United States?
3. Suppose Mount Everest were in the United States. What would
the mean of the three tallest mountains in the United States
then be?
CHALLENGE The mean height of all the land in the United
States is 763 meters. Does knowing the mean height help
you describe the shape of the land in the United States?
Explain why or why not.
Chapter 8: Mountains and Volcanoes 261