Ms. Drake 7th grade Math Measures of Central Tendency Lesson 2 Mean, Median, Mode and Range

Measures of Central Tendency Vocabulary Bar graph Box- and-Whisker Plot Circle Graph Cumulative Frequency Double Bar Graph First Quartile Frequency Table

Measures of Central Tendency Vocabulary Histogram Line Graph Lower Extreme Mean Median Mode Negative Correlation No correlation

Measures of Central Tendency Vocabulary Outlier Population Positive correlation Random Sample Range Sample

Measures of Central Tendency Vocabulary Scatter Plot Second Quartile Sector Stem-and-Leaf Plot Third Quartile Upper Extreme

Mean, Median and Mode Mean: the sum of all the data values divided by the number of data values. The mean is the same as the average

Find the mean of this data set: {2, 2, 2, 2, 2} = 10 10÷ 5 = 2 The mean is 2

Find the mean of this data set: { 1, 2, 3, 4, 5 } =15 15÷5 = 3 The mean is 3

Find the mean of this data set: { 10, 25, 31 } =66 66÷3 = 22 The mean is 22

Median: The middle term of a data set. Like the median in the middle of a highway.

To find the median for a set of data you must first put the data in ascending order. Then count by crossing off the terms on each end of the data set until you come to the middle term.

Find the median of this data: Data: 3,1,7,4,9 First put in order. Then find the middle value 1, 3, 4, 7, 9

Median: is the middle value of an odd number of data arranged in order. For an even number of data items, the median is the average of the two middle values.

Find the median for this data: 15, 3, 72, 21 First put in order: 3, 15, 21, 72 Then cross off the end values until you get to the middle

Find the average of the two middle values. 3, 15, 21, = 36 36÷ 2 =13 The median is 13

Find the median of this data: 51, 27, 33, 55, 22, 60, 48, 42, 28 First put the data in order. Then mark off from each end.

22, 27, 28, 33, 42, 48, 51, 55, 60 The median is 42

Find the median of this data set: 239, 233, 262, 245, 241, 268 First put the data in order.

Mode: is the value or values that occur most often in a set of data. Data: 8, 6, 9, 4, 3, 10, 6, 2, 5, 13 8, 6, 9, 4, 3, 10, 6, 2, 5, 13

Find the mode of this data set: 12, 3, 5, 7, 7, 12, 4,12 12, 3, 5, 7, 7, 12, 4, 12

Find the mean, median and mode of the following data. 7, 5, 26, 8, 11, 7, 6, 4, 11, 7, 2, 20

twelve pieces of data so divide by ÷ 12 = 9.5 The mean is 9.5 Mean = 114

Median 7, 5, 26, 8, 11, 7, 6, 4, 11, 7, 2, 20 First put the data in order… 2, 4, 5, 6, 7, 7, 7, 8, 11, 11, 20, 26 Then mark off the data one by one = ÷ 2 = 7

Mode Which term occurs the most? 7, 5, 26, 8, 11, 7, 6, 4, 11, 7, 2, 20 7, 5, 26, 8, 11, 7, 6, 4, 11, 7, 2, 20 The mode is 7.

Range The range of a set of data is the difference between the greatest and the least values In this data set : 4, 6, 3, 5, 7 The greatest value is 7 The least value is 3 The range is 7- 3 = 4

Find the range of this data set: The greatest value is 10 and the least value is – 2 = 11 The range is 11

Until next time, here is a web site where you can practice finding the mean, median, mode and range.

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