Transcript Lesson 11 Measures of Central Tendency

Warmup
Define.
1. mean
2. median
3. mode
4. range
5. maximum
6. minimum
Lesson 11
Measures of Central Tendency
Objective #2: Calculate measures of central
tendency (mean, median, and mode).
– Mean (a.k.a “average”): Add and Divide
– Median (a.k.a “middle”): Order and pick middle #
– Mode (a.k.a “most”): Find number repeated the most
ANSWERS
Define each of the following terms.
1. mean average
2. median middle of a group when put in sequential order
3. mode most frequently occurring
4. range maximum minus the minimum
5. maximum highest value
6. minimum lowest value
Video Lessons
Ten Marks (Scroll down to the video screen for central tendency.)
Khan Academy Video
Process
Mean
Step 1 – Add up all of the numbers given.
Step 2 – Divide the sum by the total number
of numbers added.
Process
Median
Step 1 – Put numbers in order from least to
greatest.
Step 2 – Locate the middle number
– If there is an exact middle number, that is the median.
– If there are two numbers in the middle, add them
together and divide by 2. (Find their mean)
Process
Range
Step 1 – Locate largest and smallest number
Step 2 – Subtract smaller number from larger
number (biggest number minus
smallest number.)
EXAMPLE
2 minimum, maximum, range, and median for
Identify the
Dallas and Houston for the number of months having less
than 3.5” rainfall.
Seven students in the seventh grade took a
quiz. They scored the following:
30, 30, 24, 24, 27, 37, 24.
1. To find the mean, add all of the numbers,
then divide by number of addends.
(number of numbers added)
24 + 24 + 24 + 27 + 30 + 30 + 37 = 196
196 ÷ 7 = 28
The mean is 28 points.
Seven students in the seventh grade took a
quiz. They scored the following:
30, 30, 24, 24, 27, 37, 24.
2. To find the median, arrange that data in
order from least to greatest, then find the
middle number.
24, 24, 24, 27, 30, 30, 37
The median is 27.
Seven students in the seventh grade took a
quiz. They scored the following:
30, 30, 24, 24, 27, 37, 24.
3.
To find the mode, find the number that
occurs most often.
The mode is 24.
Seven students in the seventh grade took a
quiz. They scored the following:
30, 30, 24, 24, 27, 37, 24.
4. To find the range, subtract the greatest
number and the least number. This will
show the spread of the data.
37 – 24 = 13
The range is 13 points.
Find the mean, median, and mode(s) of the data.
8, 12, 15, 17, 18, 26
ANSWER
16, 16, no mode
186, 144, 201, 164, 182, 164
ANSWER
173.50, 173, 164
The monthly charge for seven dial-up internet
service providers are listed. What is the mean
price? $10, $22, $17, $11, $16, $23, $25
ANSWER
about $17.71
Find the mean, median, mode, range,
maximum, and minimum of each set.
1. {1, 2, 2, 3, 4, 5, 11}
2. {7, 6, 1, 7, 4}
3. {7, 10, 3, 2, 5, 12}
Find the mean, median, mode, range, maximum, and
minimum of each set.
1. {1, 2, 2, 3, 4, 5, 11}
mean:4 median:3 mode:2 range:10 maximum:11 minimum:1
2. {7, 6, 1, 7, 4}
mean:5 median:6 mode:7 range:6 maximum:7 minimum:1
3. {7, 10, 3, 2, 5, 12}
mean:6.5 median:6 mode:none range:10 maximum:12 minimum:2
Extending the Learning
How will new values affect the measures of central tendency?
Select your numbers and show the measures.