This document discusses different measures of central tendency (mean, median, mode) and what each indicates. It analyzes what each measure can and cannot determine from a data set. The mean is the average and can be affected by outliers. The median is the middle number and is least affected by outliers. The mode shows the most frequent value. Choosing the best measure depends on whether you want to know the center, consider outliers, or find the most popular value. A worksheet provides examples of choosing the appropriate measure for different data sets.

1. Analyzing Measures of
Central Tendency
When to choose
Mean, Median, Mode and what
they indicate

2. Measures of Central Tendency
• These are statistical terms that try to
find the “center” of the numbers that
are in a group of data.
• Mean – average
• Median – middle
• Mode – most common or most popular
• Outlier – a number in a set of data that is
much bigger or smaller than the rest of the
numbers

3. Analysis of Mean
• What you can determine from the mean
– if numbers are above or below the mean.
– this measure can be drastically affected by the
addition or deletion of numbers to the data
• What you cannot determine
– if there were any outliers – outliers will substantially
distort the data either too high or too low.
– what individual scores were
• This is usually the best choice to describe
data unless there is an outlier.

4. Analysis of Median
• What you can determine from the median
– if numbers are above or below the halfway point.
– this measure is the least affected measurement if
new numbers are added to the data
• What you cannot determine
– if there were any outliers
– what individual scores were
• This is usually the best choice to describe
data if there is an outlier.

5. Analysis of Mode
• What you can determine from the mode
- Which number or numbers are there the most
frequently
• What you can’t determine from the mode
- Where the number is in the group of data
- What all the other numbers are
• This is usually the best choice to describe
data if you want to select the most popular
value or item.

6. Analysis of Range
• What you can determine from the range
- How far apart the numbers are
• What you can’t determine from the range
- What the numbers are in the data set
• This is usually the best choice to describe
data if you want to know the spread of the
data.

7. Choosing the best Measure of Central Tendency
(worksheet – for homework)
1. A retail store had total sales of $436,
$650, $530, $500, $650, $489, and
$423 last week. Which measure of data
would make the store’s sales last week
appear the most profitable? Explain.

8. 2. The heights of 5 starting players on the
basketball team are 75 in., 74 in., 73
in., 70 in., and 68 in. Decide whether the
mean describes the data well. Explain.

9. 3. The monthly car payments for Brandon’s
last 8 customers were
$266, $285, $285, $285, $285, $315, $325,
$344. Decide whether the mode describes
this data well. Explain.

10. 4. At the end of the winter, the seven
sweaters left in stock at Griselda’s Outlet
Store were
brown, orange, green, orange, brown, orang
e, orange and orange. Decide which
measure of central tendency is appropriate
for this data. Explain.

11. 5. The profits at 5 schools that sold Gems &
Jewels products were
$318.22, $440.79, $607.16, $1090.38, $4790.15
. Decide whether the mean or median is the
better measure of central tendency for this data.
Explain.