Transcript File

Algebra 1
Lesson 1
Exploring Measures of center and
spread
Warm up
• Find the mode, median and mean of these
data.
• 8, 4, 16, 8, 12, 19, 35, 8, 4, 11
Definitions
• Mode – value or values that occur most often.
• Mean – the sum of the values in the set
divided by the number of values in the set.
• Median – the middle value in a set when the
values are arranged in numerical order.
To find the mode
• Arrange the data in order.
• Look at each data to determine the most
frequent value.
To find the median
• Arrange the data in ascending order, from
small to big
• Find the number in the middle or find the
average of the 2 middle numbers
To find the mean
• Add all the numbers in the set.
• Divide the total with the number of data
values
Example 1
• Find the mean and median of each data set.
• a. 47, 49, 54, 50, 48, 47, 55
• b. 75, 97, 360, 84, 119, 100
Example 2
Caleb and Kim have bowled 3 games.
Their scores are shown below.
Name
Game 1
Game 2
Game 3
Caleb
151
153
146
Kim
122
139
189
Complete the table. How do you find
the average of their scores?
Average Score
Explore the data
1. How do their average scores compare?
1. Who’s game is more consistent?
1. Is Caleb’s scores farther from or closer to the
average than Kim’s?
• They bowl a fourth game, where Caleb scores 150
and Kim scores a 175. How does this affect
a. Caleb’s average?
b. Kim’s average?
• 4. Does the Game 4 score affect the
consistency of their scores? Explain.
Conclusion
• 1. Is the average an accurate representation of
Caleb’s bowling?
• 2. Is the average an accurate representation of
Kim’s bowling?
A1
• Find the mean and the median of each data
set:
• 1. The numbers of hours Cheri works each day
are 3, 7, 4, 6, and 5
• 2. Find the mean and the median .
• The weights of 6 members of a basketball
team are 125, 136, 150, 119, 150, and 143.
• 3. Find the mean and the median of 36, 18,
12, 10, and 9
Reflections
• How do you find the mode, median and mean
of a set of data.