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Math Review: line plots, bar graphs, mean, median, mode, range

Block 4 – Math

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What is a line plot?

A line plot displays data along a number line.

Each x represents one number in the data.

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Outlier

A number in a data set that is very different from the other numbers.

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Here, x’s = houses with pets

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Average Number of Emails x

x xx x xx___x___x_____x__________1 2 3 4 5 6 Emails sent today

What is the average number of emails sent today?

Remember to find the average : ADD and Divide

What is the range? What is the mode? What is the median?

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What is the outlier here?

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What is a bar graph?

A bar graph is a graph using bars to show data.

Bar graphs can be vertical or horizontal.

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Compare and Contrast

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Parts of a bar graph

Scale: Numbers that show the units used on a graph are the scale.(The numbers on the graph.)

Interval: a number which is the difference between two consecutive numbers on the scale of a graph.

The interval is 5. The graph must have labels!

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Steps for creating a bar graph.

Choose a scale. Draw and label the side and bottom of

the graph. Draw a bar on the graph for each

piece of data. Give the graph a title. The title shold

describe the subject of the graph.

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Make a bar graph.

http://nces.ed.gov/nceskids/graphing/classic/bar_pie_data.asp?ChartType=bar

Y axis – vertical (up and down) X axis – horizontal (across)

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What is the Median?

The median is the middle number when the data are listed in order.

The number of raisins in our boxes: 10, 26, 26, 27, 30, 32, 32, 32, 34

x30 is the median.

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What is the mode?

The mode is the number or numbers that occur most often in the data.

10, 26, 26, 27, 30, 32, 32, 32, 34

The mode is 32.

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What is the range?

The range is the difference between the greatest and the least number in the data.

10, 26, 26, 27, 30, 32, 32, 32, 34

The greatest number is 34. The least number is 10.

34 – 10 = 24. The range is 24.

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What is the mean?

The mean is the average. It is found by adding all the numbers in a set and dividing by the number of values.

10, 25, 20, 5, 20 The sum is 75. We added 5 numbers. Divide 75 by 5. The average or mean is 15.

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Mean

The blocks that are all the same height show the average or mean.

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Practice at this interactive website.

http://www.bbc.co.uk/schools/teachers/ks2_activities/maths/mode_median_mean.shtml

or Here http://www.bbc.co.uk/bitesize/ks3/mat

hs/handling_data/measures_average/activity/