1. Mean, Median, Mode
and Range

2. The mean is the sum of all the items, divided by the number of items in the set. The mean is sometimes called the average.

3. Brady is growing 8 plants for science class
Brady is growing 8 plants for science class. He measured the height of each plant after 14 days and recorded the data in a graph.

4. 1 +3 +4 +2 +6 +8 +11 +5 = Find the mean height of Brady’s plants.
What is the height of each plant?

5. Find the mean height of Brady’s plants.40 ÷ 8 = 5

6. The median is the middle value when the data are in numerical order.
“middl’un”
The median
is the middle
value when
the data are
in numerical
order.

7. 5, 2, 7
2 is in the middle.
Is it the median?
No, you must first put
the numbers in order.
2, 5, 7

8. If there are an even number of items, the median is the mean of the two middle values.
2, 3, 4, 29
3.5

9. the
“modst”
The mode is
the value or
values that
occur most
often.

10. There may be more than one mode for a data set
There may be more than one mode for a data set. When all values occur an equal number of times, the data set has no mode.

11. Find the mode for each.
3, 3, 5, 7, 7, 7, 10
2, 2, 4, 6, 8, 9, 9, 14
5, 6, 9, 11, 13, 15
0 is a number
Don’t say “zero”
“no mode”
say

12. Mean, median and mode
are called
Measures of Center

13. 20 85 65 The range is the difference between
the least and greatest values in the set. 65

14. Finding the Mean, Median, Mode and Range of a Data Set
Depths of Puddles (in.) 5 8 3 4 2 1
Start by writing the data in numerical order.
1, 2, 3, 4, 5, 5, 8
range: 8 – 1 = 7
Subtract least value from greatest value.
mean: = 28
28 ÷ 7 = 4
Add all values.
Divide the sum by the number of items.
median: 4
There are an odd number of items, find the middle value.
mode: 5
5 occurs most often.
The range is 7 in.; the mean is 4 in.; the median is 4 in.; and the mode is 5 in.
Course 1

15. Number of Points Scored
Finding the Mean, Median, Mode and Range of a Data Set
Number of Points Scored 96 75 84 7
Write the data in numerical order.
7, 75, 84, 96
range: 96 – 7 = 89
mean: 4
= 65.5
median: 7, 75, 84, 96
There are an even number of items, so find the mean of the two middle values. 2
= 79.5
mode: none
The range is 89 points; the mean is 65.5 points; the median is 79.5 points; and there is no mode.

16. Finding the Mean, Median, Mode and Range of a Data Set
Rainfall per month (in.) 1 2 10 5 6 9
Start by writing the data in numerical order.
1, 2, 2, 5, 6, 9, 10
range: 10 – 1 = 9
Subtract least value from greatest value.
mean: = 35
35 ÷ 7 = 5
Add all values.
Divide the sum by the number of items.
median: 5
There are an odd number of items, find the middle value.
mode: 2
2 occurs most often.
The range is 9 in.; the mean is 5 in.; the median is 5 in.; and the mode is 2 in.

17. Number of Points Scored
Finding the Mean, Median, Mode and Range of a Data Set
Number of Points Scored 53 26 47 12
Write the data in numerical order.
12, 26, 47, 53
range: 53 – 12 = 41
mean: 4
= 34.5
median: 12, 26, 47, 54
There are an even number of items, so find the mean of the two middle values. 2
= 36.5
mode: none
The range is 41 points; the mean is 34.5 points; the median is 36.5 points; and there is no mode.