1. Measures of Central Tendency
Vocabulary
Range:
Measures of Central Tendency
Mode: the data item that occurs the most times.
* It is possible for a set of data to have no mode
or more than one mode.
Use the mode
Mean: the average
Use the mean
Median: the middle value in the set when
the numbers are arranged in order.
* If there are two in the middle, find their average.
Use the median
Outlier:
How do you find the range?
Tune – Home, Home on the Range
How do you find
It’s the difference of
The lower
Are the only
Measures the spread of data; the difference
between the greatest and the least data value.
the range?
the extremes.
extreme and the upper extreme
two values you need.
when the data is categorical (non-numeric) or when choosing the most popular item.
Mean, Median and Mode Song
Tune – “Row, Row, Row Your Boat”
Mode, mode, mode’s
Average
Median, median, median, median’s
Always
to describe the middle of a set
of data that DOES NOT have an outlier.
the most.
is the mean.
in between.
to describe the middle of a set of data that DOES have an outlier.
a data value that is much higher or lower
than the other data values in the set.

2. Use this data set to answer the following questions:
14, 10, 16, 11, 20, 19, 18, 16, 10, 16
1. What is the range of the data?
2. Does the data set have any outliers?
3. Find the median.
4. Find the mode.
5. Find the mean.
6. The prices of seven pairs of shoes are $45, $23, $63, $23, $81, $75 and $47. What is the range in the price of the shoes?
$23 C. $51
$47 D. $58
7. The prices of nine backpacks are $43, $21, $53, $32, $32, $23, $61, $67 and $37. What is the median price of the backpacks?
A. $32 C. $41
. $37 D. $46
8. The prices of five snacks are $1.50, $2.00, $3.00, $.75 and $ What is the mode of the snacks?
0 C. no mode
$2.50 D. $3.00