Download Statistics, Data Analysis, and Probability

UNIT 3:
Statistics, Data
Analysis, and
Probability
6PS 1.1
Mean, Median,
Mode
Period: 2, 4, 6: 1/8/13
Period 3, 5: 1/9/13
MODE:
• Mode is the most frequently
occurring number in a set.
Example:
For the set [3, 2, 8, 2, 4]
The number that appears most
often is 2, so 2 is the mode.
Big Note: Some sets will have
multiple modes.
Example:
For the set [3, 2, 8, 2, 4, 3]
The numbers that appear most
often are both 2 and 3, so the
modes of this set are 2 and 3.
continued…Mode
• For the set [3, 2, 8, 4]
Since no numbers appear more
than any other numbers, there
is no mode for this set.
White Board CFU
• The data below shows the number of
kilowatt-hours of electricity used last
month at each of the houses on Harris
street.
620, 570, 570, 590, 560, 640, 590, 590,
580
What is the mode of this data?
Mean
• Mean is often referred to as the
“average” of a set of numbers.
• To find the mean, add up all the values,
and divide the sum by the number of
values in the set.
MEAN= (sum of a group of numbers)
(NUMBER of numbers in the group)
Example
In calculating mean…
• If the values are 15, 45, and
33
• The sum is 15+45+33=93
• The number of numbers in the
set is 3
• So 93÷3=31
Whiteboard CFU
Parisa’s four math test scores
were 7, 8, 10, and 6. Hector’s
test scores were 6, 7, 9, and
10. Charles’ test scores were
8, 10, 10, and 9.
What is Hector’s mean score?
Whiteboard CFU
• Parisa’s four math test scores
were 7, 8, 10, and 6. Hector’s
test scores were 6, 7, 9, and
10. Charles’ test scores were
8, 10, 10, and 9.
• Who had the highest mean?
Median
• Median is the middle number
in an ordered set.
• You must put the numbers in
order.
• In an even set of numbers, the
median is the mean of the two
middle terms.
Example #1
• For the set [3, 7, 8, 2, 4]
These numbers aren’t in order,
so place them in order:
continued…
2, 3, 4, 7, 8
The middle number is 4, so 4 is
the median.
Whiteboard CFU
• Find the median for the
following set
[3, 7, 8, 2, 4, 6]
ANSWER
• 4 and 6 are both in the middle
• The average of 4 and 6= 5, so
the median of this set is 5.
Independent Practice 6PS 1.1
Find mean, median, and mode
1) 18, 18, 15, 18, 18,
2) 94, 69, 84, 69, 90
3) 4, 18, 18, 23, 23, 19, 8,
4) 12, 15, 16, 17, 15, 17
5) 16, 3, 3, 3, 8, 24
6) 22, 5, 22, 13, 12, 24,
7) 23, 1, 1, 18, 1, 3, 18, 3
8) 23, 10, 2, 6, 10, 14, 1