Mean, Median, Mode and Range

Summarize Data Using Mean, Median, Mode, and Range

Use the textbook pages to complete the lesson. Show your work in your book.

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​Lesson 8-2

pages 459-466

Try It!

Find the mean, median, mode and range of the following data.

4, 6, 8, 3, 2, 1, 0, 12, 9

(Check your work on the next slide.)

0, 1, 2, 3, 4, 6, 8, 9, 12

Mean: 0 + 1 + 2 + 3 + 4 + 6 + 8 + 9 + 12 = 45 ÷ 9 = 5

Median: 4

Mode: there is no mode (don't say 0 because that is a value)

Range: 12 - 0 = 12

​Do You Know How?

Please complete page 463 # 4, 5, 6 in your textbook.

Then work on Practice & Problem Solving page 464 #7-14.

Show all of your work. I will be checking your textbook tomorrow.

Have a great day!

3, 4, 5, 7, 7, 11, 12, 13

You can see if numbers repeat.

You can see the range of numbers when put in order. You can see the smallest (minimum) and largest (maximum).

​Focus on Math Practices

Jamal says that the middle value in a data set is the number that occurs most often (mode). Evan disagrees. Why does Jamal say what he says and why does Evan disagree? Explain.

In this particular case, the middle is 7 and is also repeated the most. It is true for this data, but the mode is not always the middle number.

To calculate mean, add all the numbers in the data set, then divide by the number of values in the set.

95 + 87 + 84 + 81 + 83 = 430

430 ÷ 5 = 86

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A mean is a measure of center which summarizes data with a single value.

​Try It!

The next week, Maria bowls a 151-point game. The other bowlers math their scores. What is the new mean final score for the team? Explain.

How did the mean final score change from the Example to the Try It!?

(Write your answer and check your work on the next slide.)

Try It!

The mean final score increased because 81 was replaced by 151.

95 + 87 + 84 + 151 + 83 = 500

500 ÷ 5 = 100

100 is the new mean.

When finding the median:

1. Put the numbers in order.

2. Find the middle number.

(If there are two numbers in the middle, find the average of those two numbers.)

Let's summarize:

Mean is the average.

Median is the middle.

Mode is the number repeated most often.

Try It!

Nadia's grades on four quizzes were 95, 75, 85, and 95. Find the mean, median, and mode for Nadia's grades.

(Check your work on the next slide.)

​75, 85, 95, 95

Put your numbers in order from least to greatest.

Mean: 75 + 85 + 95 + 95 = 350 ÷ 4 = 87.5

Median: 85 + 95 = 180 ÷ 2 = 90

Mode: 95

Range is maximum - minimum

The greatest value (maximum) minus the least value (minimum).

Mean, Median, and Mode are all "Measures of Center".

Range is a measure of variability.

​Try It!

Find the mean, median, mode and range of the following set of data.

4, 6, 8, 3, 2, 1, 0, 12, 9

(Check your work on the next slide.)

0, 1, 2, 3, 4, 6, 8, 9, 12

Mean: 0 + 1 + 2 + 3 + 4 + 6 + 8 + 9 + 12 = 45 ÷ 9 = 5

Median: 4

Mode: there is no mode (do not say the mode is zero because 0 could be a data value)

Range: 12 - 0 = 12

​Time to Practice

Please complete page 463 # 4-6 and page 464 # 7-14.

I will check these pages tomorrow. When finished, you can work on your Heartbreak Hitman or ExactPath.

Have a great day - see you tomorrow!

😁