Box and Whisker Graphs

Title: Boxplots

WARM UP: ​WRITE THIS IN YOUR NOTES, draw the picture, and write the definitions :

Boxplots show the "five number summary" of the data, dividing the data into quarters (25%).

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Minimum: The lowest value of the data set

​First Quartile (Q1): ​Middle of the lower half of the data set. 25% of the data lies below this value and 75% lies above.

​Median: Middle of the data set. Half the data (50%) lies below this value and half (50%) lies above. ​

​Third Quartile (Q3): Middle of the upper half of the data set. 75% of the data lies below this value and 25% lies above.​

​Maximum: The highest value of the data set.

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​Two additional pieces of information that can be determined are:

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The Interquartile Range (IQR) = Q3 - Q1

The Range = Max - Min​

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These pieces of information will show the extent to which the data is located near the center or near the extremes of the data set.​

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Measures of Spread

Match

Match the following terms with their definitions

• Minimum (Min)

• First Quartile (Q1)

• Median (Q2)

• Third Quartile (Q3)

• Maximum (Max)

The lowest value of the data set

Middle of the lower half of the data set. 25% of the data lies below this value and 75% lies above.

Middle of the data set. Half the data (50%) lies below this value and half (50%) lies above.

Middle of the upper half of the data set. 75% of the data lies below this value and 25% lies below.

The highest value of the data set

• The lowest value of the data set

• Middle of the lower half of the data set. 25% of the data lies below this value and 75% lies above.

• Middle of the data set. Half the data (50%) lies below this value and half (50%) lies above.

• Middle of the upper half of the data set. 75% of the data lies below this value and 25% lies below.

• The highest value of the data set

Multiple Choice

What do points B and D represent on the box plot?

• Mean and Mode

• Mean and Median

• Least and Greatest Value

• First and Third Quartiles

Multiple Choice

What do points A and E represent on the box plot?

• Mean and Mode

• Mean and Median

• Least and Greatest Value

• First and Third Quartiles

Multiple Choice

What does point C on the box plot represent?

• First Quartile

• Median

• Third Quartile

• Mean

Multiple Choice

What is the median of the data?

• 200

• 100

• 90

• 140

Multiple Choice

What value is the lower quartile?

• 66

• 58

• 60

• 64

Multiple Choice

What data value is the upper quartile (Q3)?

• 64

• 62

• 66

• 58

​Example for your notes:

Multiple Choice

Now lets find the median, what do you do to find it?

• Cross off my numbers in pairs until I get one or two in the middle

• Add all of my numbers together

• Find the most common one

• Subtract the largest and smallest

Multiple Choice

We have two numbers in the center, what do we do to find the median?

• Nothing, we have two medians

• Add them and divide by 2

• We choose the one we like the most

Fill in the Blank

What is the median? (Your numbers were 15 & 17)

Multiple Choice

What is the interquartile range? (Q3 - Q1)

• 33

• 11

• 26

• 23

Multiple Choice

Which of the films do you think you would not be allowed to legally watch at the cinema?

• Film A

• Film B

• Film C

• Cannot tell

Multiple Choice

What percentage of film B’s audience were between 15 and 30 (the box)?

• 25%

• 50%

• 75%

• Cannot tell

Multiple Select

Which of these comparisons are correct?

• Boys weigh more than girls on average

• The lightest girl is lighter than the lightest boy

• The heaviest boy is the same weight as the heaviest girl

• Girls weight is less consistent than boys

Multiple Choice

What is the minimum value?

• 64

• 58

• 66

• 60

Multiple Choice

What is the maximum value?

• 58

• 66

• 64

• 60

Multiple Choice

What data value is the upper quartile (Q3)?

• 64

• 62

• 66

• 58

Multiple Choice

What value is the lower quartile?

• 66

• 58

• 60

• 64

Multiple Choice

What is the median?

• 62

• 58

• 66

• 60

Multiple Choice

Which city has a higher median?

• Millersburg

• Arcadia

Multiple Choice

Which best represents the Interquartile Range

• 15

• 93

• 85

• 78

Multiple Choice

What is the range of the set of data?

• 70

• 65

• 80

• 55

Multiple Choice

Which plot has a median of 50?

• Plot 1

• Plot 2

• Plot 3

• Plot 4

Multiple Choice

Which class has the highest test score?

• 1st Period

• 2nd Period

Multiple Choice

What is the interquartile range (IQR)?

• 4

• 64

• 60

• 8

Multiple Choice

What percent of students have a height between 58 inches and 60 inches?

• 25%

• 50%

• 75%

• 100%

Multiple Choice

What percent of students have heights between 60 inches and 66 inches?

• 75%

• 50%

• 100%

• 25%

The Rest of Class - Homework

You can get in groups and work together on this.

Due next class

If you finish work on IXL

Homework Packet

Choose any that seem hard for you.

Try and get at least 2 done to above 50%

IXL