Page 151 - Math Course 2 (Book 2)

Measure of Central Tendency

Real World Example
Solve the Test Item

$8340
QUIZ SCORES Mean $1290 + $1400 +...+$2650 = = $1668
5
5
The quiz scores for students in a math class are 8, Mode $1400
7, 6, 10, 8, 8, 9, 8, 7, 9, 8, 0, and 10. Which measure
of central tendency best represents the data?
Then find the measure of central tendency. Median $1290, $1400, $1400, $1600, $2650

The data value 0 appears to be an extreme value. Answer The mean is the highest
So, the median and mode would best represent measure, so the answer is C
the data.

0, 6, 7, 7, 8, 8, 8, 8, 8, 9, 9, 10, 10 Your Turn!

Choose an Appropriate Measure
Answer The median and mode are 8.

BOWLING
Check Jenny’s bowling scores are 146, 138, 140, 142, 139,
You can check whether the median best represents 138, and 145. Which measure of central tendency
the data by finding the mean with and without the best represents the data?
extreme value.
A. mean
mean with extreme mean without extreme B. median
value value C. mode
D. cannot be determined
sum of values 98 sum of values 98
= =
number of values 13 number of values 12
Answer
≈ 7.5 ≈ 8.2

The mean without the extreme value is closer to the
median. The extreme value decreases the mean by
about 0.7. Therefore, the median best represents
the data.
Real World Example

BIRTH WEIGHT
Standardized Test Example The birth weights of ten newborn babies are given
in pounds: 7.3, 8.4, 9.1, 7.9, 8.8, 6.5, 7.9, 4.1, 8.0,
SALARIES 7.5. Tell which measure of central tendency best
represents the data. Then find the measure of
The monthly salaries for the central tendency.
employees at Bob’s Book Store
are: $1290, $1400, $1400, $1600, A. mean, 7.53
$2650. Which measure of central tendency should B. median, 7.9
Bob’s Book Store’s manager use to show new em- C. mode, 7.9
ployees that the salaries are high? D. cannot be determined

A mode B median
C mean D cannot be determined
Answer
Read the Test Item
To find which measure of central tendency to use,
find the mean, median, and mode of the data and
select the greatest measure.
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