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6-2 Mean, Median, Mode and Range6-2 Mean, Median, Mode, and Range

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Warm UpWarm Up

Lesson PresentationLesson PresentationProblem of the DayProblem of the Day

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6-2 Mean, Median, Mode and RangeWarm UpMrs. Cowan classes and Mrs. Smith classes are competing for the best overall class average on the surface area test.

1.Of both classes which average appears most often?

2. List Mrs. Cowan’s class averages in order from least to greatest.

3. Find the range of Mrs. Cowan’s class averages. (subtract the greatest average from the least average)

4.Which class has the highest overall average on the Surface Area Test? hint: add all the test scores together. Then, divide by 4. do the same for both classes.

Mrs. Cowan’s Class Average1st Period – 752nd Period – 813rd Period – 744th Period -- 85

Mrs. Smith’s Class Averages 1st Period – 772nd Period – 723rd Period – 754th Period -- 83

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6-2 Mean, Median, Mode and Range

Learn to find the range, mean, median, and mode of a data set.

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6-2 Mean, Median, Mode and Range

Vocabularyrangemeanmedianmode

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6-2 Mean, Median, Mode and Range

Players on a volleyball team measured how high they could jump. The results in inches are recorded in the table.

One way to describe this data set is to find the mean. The mean is the sum of all the items divided by the number of items in the set. Sometimes called the average. The mean of this set of data is the average height that the vollyball team could jump.

13 23 21 20 21 24 18

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6-2 Mean, Median, Mode and RangeAdditional Example 1A: Finding the Mean of a Data

Set

Depths of Puddles (in.)5 8 3 5 4 2 1

mean: 5 + 8 + 3 + 5 + 4 + 2 + 1 = 28

28 ÷ 7 = 4

The mean is 4 inches.

Add all values.

Divide the sum by the number of items.

Find the mean of each data set.

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6-2 Mean, Median, Mode and RangeAdditional Example 1B: Finding the Mean of a Data

Set

mean: 96 + 75 + 84 + 7 = 263

183 ÷ 4 = 65.5

The mean is 65.5 points. The average number of points scored is 65.5.

Add all values.

Divide the sum by the number of items.

Find the mean of each data set.

Number of Points Scored96 75 84 7

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6-2 Mean, Median, Mode and RangeCheck It Out: Example 1A

Find the mean of each data set.

Rainfall per month (in.)1 2 10 2 5 6 9

mean: 1 + 2 + 10 + 2 + 5 + 6 + 9 = 35

35 ÷ 7 = 5

The mean is 5 inches.

Add all values.

Divide the sum by the number of items.

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6-2 Mean, Median, Mode and RangeCheck It Out: Example 1B

Find the mean of each data set.

mean: 53 + 26 + 47 + 12 = 138

138 ÷ 4 = 34.5

The mean is 34.5 points. The average number of points scored is 34.5.

Add all values.

Divide the sum by the number of items.

Number of Points Scored53 26 47 12

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6-2 Mean, Median, Mode and Range

Some other descriptions of a set of data are called the median, mode, and range.

•The range is the difference between the least and greatest values in the set.

•The median is the middle value when the data are in numerical order, or the mean of the two middle values if there are an even number of items.

•The mode is the value or values that occur most often. There may be more than one mode for a data set. When all values occur an equal number of times, the data set has no mode.

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6-2 Mean, Median, Mode and RangeAdditional Example 2: Finding the Mean, Median,

Mode, and Range of a Data Set

Write the data in numerical order. 11, 12, 14, 15

range: 15 – 11 = 4

mean: 12 + 11 + 14 + 15 4

= 13

median: 11, 12, 14, 15 12 + 14

2= 13

mode: none

The mean is 13, the median is 13, there is no mode, and the range is 4.

There are an even number of items, so find the mean of the two middle values.

Find the mean, median, mode, and range of the data set. Car Wash Totals

6th Grade 12 7th Grade 118th Grade 14 9th Grade 15

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6-2 Mean, Median, Mode and RangeCheck It Out: Example 2

Write the data in numerical order. 11, 14, 17, 22

range: 22 – 11 = 11

mean: 17 + 11 + 22 + 14 4

= 16

median: 11, 14, 17, 22 14 + 17

2= 15.5

mode: none

The mean is 16, the median is 15.5, there is no mode, and the range is 11.

There are an even number of items, so find the mean of the two middle values.

Find the mean, median, mode, and range of the data set. Bake Sale Totals

6th Grade 17 7th Grade 118th Grade 22 9th Grade 14

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6-2 Mean, Median, Mode and Range

Lesson QuizUse the following data set: 18, 20, 56, 47, 30, 18, 21.

1. Find the range. 2. Find the mean.

3. Find the median. 4. Find the mode.

5. Bonnie ran a mile in 8 minutes, 8 minutes, 7 minutes, 9 minutes, and 8 minutes. What was her mean time?

38 3021 18

8 minutes