7th Grade Math

Lesson 1B Measures of Central Tendency 493

Choose an Appropriate

Measure

EXERCISE The following set of data shows the number of push-ups

Rufio did in one minute for the past 5 days: 24, 21, 28, 27, and 26.

Which measure of central tendency best represents the data?

Justify your selection and then find the measure.

Since the data set has no extreme values or numbers that are

identical, the mean would best represent the data.

Mean __^24 +^21 +^28 +^27 +^26

5

= _^126

5

or 25.2

The measure 25.2 push-ups best represents the data.

The median, 26, is also appropriate.

c. CLOTHING The following set of data shows the costs of pairs of

jeans for various stores: $25.99, $29.99, $34.99, $19.99, $45.99.

Which measure of central tendency best represents the data?

Justify your selection and then find the measure.

Real-World Link

Roy Berger of Canada

currently holds the

record for the most

push-ups in one

minute at 138.

RR

Find the mean, median, and mode for each data set. Round to the nearest

tenth if necessary.

Example 1

1. number of states visited: 4, 0, 3, 19, 2, 0, 5, 7


2. inches of rainfall: 3.5, 2.8, 1.4, 1.2, 12.5, 2.3, 0.4


3. 
   

   Number of Calories in Vegetables
   (1 serving)

   
   

12 6 15 14 5 18 14

20 24 10 19 55 14 19

Example 2 4. RETAIL A department store recorded the time, in minutes, it took to help

customers: 4, 3.5, 18, 1.5, 2.5, 5, 4.5, 6, 2.5, 3.5. Which measure is most

affected by the extreme value?

Example 3 5. VIDEO GAMES The table shows the cost of Video Game Prices

$28 $19 $14 $31

$15 $29 $37 $22

various video games. Which measure of

central tendency best represents the data?

Justify your selection and then find the

measure.

490_497_C09_L1_895130.indd 493 1/11/10 9:31 AM