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Bar Graphs

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Bar Graph: uses either horizontal or vertical bars to COMPARE data.

When to use this graph:

To make COMPARISONS between different items easy to identify.

Examples: Use Bar Graphs when comparing…

Bar Graphs

Bar Graphs

3. On which day did she talk on the phone half as long she did on Monday?

4. How many minutes did she talk during all five days?

Thursday

202 minutes

1. On which day did she talk the longest? Monday

2. How many minutes did she talk on Monday and Tuesday? 99 minutes

HistogramsN

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100-90 89-80 79-70 69-60 59 & under

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First Semester Exam Grades

Histogram: type of bar graph used to display the frequency of data that has been organized into equal intervals. In a histogram, the bars touch and both axes show numerical data.

When to use this graph: We use a histogram to identify the number of data points that occur within a range of values.

Examples: Use Histograms when finding how often values occur within a range of data.

Histograms

1. What is the cost of most cameras?

$100 - 199

Histograms

2. Which statement is NOT true?

A. Four cameras are priced from $300 - $399.

B. The mode of the data is $100 - $199.

C. The most expensive camera is $499.

D. There are 32 cameras in the data set.

Circle Graphs42%

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Activity Teenagers Are Most Willing to Give Up

Reading

Watching TV

Music

Circle Graph: shows how the parts of a complete set of data are related. The circle represents 100% of the data.

When to use this graph: We use circle graphs to compare percents.

Examples: Use Circle Graphs when comparing percents.

Circle Graphs

1. Which country has the most petroleum exports?

2. How many times more exports does Iran have than Qatar? 3 times more

Stem & Leaf Plots

Stem Leaf

2 2 1 1 3 3 10 3 8 0 8 5 8

Stem-and-Leaf Plot: the data is organized from LEAST to GREATEST. The digits of the least place value form the leaves , and the next place value digits form the stems.

When to use this graph: to compare LARGE sets of data values and to easily determine the _________ value. MEDIAN

Examples: Use Stem & Leaf Plots when comparing LARGE sets of data…

Stem and Leaf Plot

1. What is the range of gold medals won?

2. Find the median number of gold medals won.

Gold Medals Won at the 2004 Summer Olympics.

35 – 6 = 29

10

Stem Leaf

1

2

3

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2 3

43 4 5 5 6

6

3. Make a stem and leaf plot using the following data:23, 36, 25, 13, 24, 25, 32, 33, 17, 26, 24

Line Plots

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Line Plot: a diagram that shows the frequency of the data on a number line.

When to use this graph: to find the _______ of a set of data. MODE

Examples: Use Line Plots when finding how often values occur.

Line Plots

What is the largest value? ____ Smallest? ____

1. So, the range is ____

2. What is the mode? ____

Shoe Sizes at a Family Reunion

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0 1 2 3 4 5 6 7 8 9

Line Graphs

Line Graph: shows trends and change over time

When to use this graph: To show changes over time. They can be useful for predicting future events.

Examples: Use Line Graphs when comparing change over time.

Line Graphs

1. During which months was the temperature below 40° Fahrenheit?

December, January, February

Line Graphs

2. True or False: The temperature increases between September and October.

3. True or False: The difference between the highest and lowest temperature is about 50°F.

Bar Graph

Histogram

Line Plot

Stem and Leaf Plot

Circle Graph

Line Graph

1. A chemist wants to organize calculations of atomic mass numbers so she can find the median value.

2. A teacher wants to know how many students made A’s, B’s, C’s, D’s, and F’s on the last exam.

3. State officials want to show how a state’s population changed over time.

4. A student wants to compare the different types of pets that people own.

5. A tennis coach wants to show the mode in a set of tennis scores.

6. A biologist wants to show the relative percentages of people who have different eye colors.

Example: Make a stem-and-leaf plot of the data below. Then find the range, median, and mode of the data.

42, 45, 37, 46, 35, 49, 47, 35, 45, 63, 45

First, order the data from least to greatest.

35, 35, 37, 42, 45, 45, 45, 46, 47, 49, 63

The tens digits form the stems, and the ones digits form the leaves.

Mode = ____ Median = ____Range = ___________

45

45

63 – 35 = 28

Circle Graph

True or False: Kuwait exports twice as much as the United Arab Emirates.

Box and Whiskers Plots

Lower extreme: the lowest or smallest value in a set of data

Lower quartile or first quartile: the median of all data below the median

Median or second quartile: the middle value of the set of data. If there are two values in the middle, the median is the average of the two values

Upper quartile or third quartile: the median of all data above the median

Upper extreme: The biggest value in the set

Lower extreme

Lower quartile

Upper extreme

Upper quartile

Median

Construct a box and whiskers plot for the data set: {5, 2, 16, 9, 13, 7, 10}

Draw a rectangle or box starting from the lower quartile to the upper quartile. Draw a vertical segment too to represent the median

First, you have to put the data set in order from greatest to least or from least to greatest

From least to greatest we get :

Since the greatest value in the set is 16, the upper extreme is 16

2    5    7    9    10     13    16

Since the smallest value in the set is 2, the lower extreme is 2

Box and Whiskers PlotsNow, look carefully at the set:  2    5    7    9    10     13    16

You can see that 9 is located right in the middle of the set of data

Therefore, 9 is the median

Box and Whiskers PlotsNow to get the lower extreme, you need all data before the median or 9

2    5    7    9    10     13    16

In bold right above we show all data before 9, so  2    5    7   

Since the value in the middle for the set   2    5    7    is 5, the lower extreme is 5

Box and Whiskers PlotsFinally, to get the upper extreme, you need all data after the median or 9

2    5    7    9    10     13    16

In bold right above we show all data after 9, so  10    13    16   

Since the value in the middle for the set   10    13    16    is 13, the upper extreme is 13

Box and Whiskers Plots

Draw a rectangle or box starting from the lower quartile to the upper quartile. Draw a vertical segment too to represent the median

Box and Whiskers Plots

Finally, draw horizontal segments or whiskers that connect all five dots together.

The box and whiskers plot for {5, 2, 16, 9, 13, 7, 10} is :