Mean Median Mode RangeGLE – DP 2a 2b

Different representations using

Same information.

Measures of Center

Define

• Mean

• Median

• Mode

• Range

Mean: The sum of all values divided by the number of addends.

Median: the middle value when values are written in numeric order.

Mode: - in a data set the mode is the value that occurs most often. A data set can have no mode, one mode or more than one mode

Range: - the difference between the greatest value and the least value

 What DO you do when someone asks you to find the range, mean, median and mode of a set of numbers?

A. I raise my hand and ask if I can go home nowB. I hide. C. I get really quiet and hope the teacher doesn't see me!

The answer is NONE OF THE ABOVE! You simply follow these steps to Success:

Step 1: Organize your data by listing it from the smallest to largest number!

For example, if your data set was made up of the numbers (4, 2, 1, 3, 5), you would list them from smallest to largest as: (1, 2, 3, 4, 5).

Step 2: Find the Range: The range of the data set is the difference between the largest and smallest number in the set.

To find the range, you simply subtract the smallest number from the largest number in the set.

                                        

In our sample data set the largest number is 5 and the smallest number is 1.

1, 2, 3, 4, 5)

5 - 1 = 4The range of this set is 4.

1. Your data set is (3, 6, 2, 7, 1). What is the range of this set of numbers?

2. Your data set is (24, 13, 67, 45, 78, 35)

3. 14, 8, 4, 21, 15, 10

Step 3: Find the Mean

The mean of the data set is its average.

To find the mean you add up all the numbers and divide the answer by how many numbers you have.

Try it! Add (1, 2, 3, 4, 5) on the calculator and then divide the answer by 5. (The / key means divide.)

1. Your data set is (3, 6, 2, 7, 1). What is the mean of this set of numbers?

2. Your data set is (24, 13, 67, 45, 78, 35)

3. 14, 8, 4, 21, 15, 10

Step 4: Find the Median: The Median is the number which is in the exact middle of the data set.

In our sample set (1, 2, 3, 4, 5), 3 is the number whichis exactly in the middle, so 3 is the median of this set

(1, 2, 3, 6, 7). What is the median of this set of numbers?

2. Your data set is (13, 24, 45, 67, 78) What is the median of this set of numbers?

3. Your data set is ( 4, 8, 10, 15, 21) What is the median of this set of numbers?

4. Your data set is 1, 2, 5, 10, 39

Step 5: Find the Mode:

The Mode is the number that appears the most often if you are working with only one variable.

We are working with one variable, a set of numbers. To show how to figure out the mode, we need to change our sample set because each number only appears once in it.

THE NEW SAMPLE SET: (2, 4, 4, 6, 8, 10).

4 appears more than any other number in this set so 4 is the mode of the set

1. Your data set is (4, 23, 5, 4, 7, 8). What is the mode of this set of numbers?

Your data set is (13, 24, 10, 56, 13, 19)

(27, 12, 34, 21, 27, 34)

Mean median mode interactive activity

Mean

Median

Mode

Range

I get it!!!

Homework

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#18 #19

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