Chapter 9 Statistical MeasuresDate: Lesson 9.1 Introduction to StatisticsEssential Question

How can you tell whether a question is a statistical question?

Vocab Word Definitionthe science of collecting, organizing, analyzing, and interpreting data

Example:

Nonexample:

a question for which you do not expect to get a single answer

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Identifying Statistical Questions

1) Which fo the following are statistical questions? Explain how you know.

a) What is your favorite fruit? _________________________________________________________________________________________________

b) How many bricks are in this wall? _________________________________________________________________________________________________________________________________________________________

c) How many pickles are in a pickle jar? _______________________________________________________________________________________

Answering a Statistical Question

2) How old are people who retire early?a) Is this a statistical question? Explain. ________________________________________________________________________________________________________________________________________________________________

b) Display the data in a dot plot. Identify any clusters, peaks, or gaps in the data.

c) Use the distribution of the data to answer the question. ________________________________________________________________________________________________________________________________________

Using a Dot Plot 3) The dot plot shows the times of sixth grade students in a 100-meter race.

a) How many students ran in the race? ______________________b) How can you collect these data? What are the units?

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c) Write a statistical question that you can answer using the dot plot. Then answer the question.____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Chapter 9 Statistical MeasuresDate: Lesson 9.2 MeanEssential Question How can you find an average value of a data set?Vocab

Word Definitionthe average of a set of data

Example:Data: 8, 5, 6, 9

Mean:

Finding the Mean 1) How many quarters do people bring to a batting cage?

Comparing Means 2) The double bar graph shows the monthly rainfall amounts for two cities over a 6 month period. What is the average rainfall for each city?

Compare the mean monthly rainfalls. ____________________________________________________________________________________________________________________________________________________________________

Vocabulary Word Definitionthe data value that is much greater or much less than the other values; _______________ can affect the mean if they are included in the data set.

Finding the Mean With and Without an Outlier

3) Below are the weights (in pounds) of dogs at a kennel. 48, 50, 55, 60, 8, 37, 50a) Graph the weights on a number line. Identify the outlier.

b) Find the mean with the outlier _________________

Find the mean without the outlier. ____________________

c) Describe how the outlier affects the mean. ______________________________________________________________________________________________________________________________________________________________________________________________________________________________

Finding the Mean With and Without an Outlier

4) Below are the prices for flights from Miami to San Juan. $456, $512, $516, $900, $436, $516a) Graph the prices on a number line. Identify the outlier.

b) Find the mean with the outlier _________________

Find the mean without the outlier. ____________________

c) Describe how the outlier affects the mean. ___________________________________________________________________________________________________________________________________________________________

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Chapter 9 Statistical MeasuresDate: Lesson 9.3 Measures of CenterEssential Question In what other ways can you describe an average of a data set?Vocab Word Definition

measure that describes the typical value of a data set

the middle number in a set of numbers that are in order from least to greatestvalue or values that occur most often; data sets can have one _________, more than one _________, or no ________.

Find the median and mode of the data.

1) 20, 4, 17, 8, 12, 9, 5, 20, 13median ____________mode _____________

2) 100, 75, 90, 80, 110, 102median ____________mode _____________

Create a frequency table and find the mode.

3)

The mode is _______________________

Find the mean, median, and mode of the sneaker prices. Which measure best represents the data?

4)

Removing an Outlier

5) Identify the outlier form problem number 4. Find the mean, median, and mode without the outlier. Which measure does the outlier affect the most?

mean ____________ median ____________ mode ___________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Chapter 9 Statistical MeasuresDate: Lesson 9.4 Measures of VariationEssential Question How can you describe the spread of a data set?Vocab Word Definition

a measure that describes the distribution of a data set

the difference between the greatest value and the least value; The _______________ is a measure of variation.Example: 14, 25, 24, 11, 18, 19, 8, 15

Mean ______ Median _______ Mode _______________________________________________________________________________________________________________________________________________________________________________

largest number ___________smallest number __________

Finding the Range The ages of people in line for a roller coaster are15, 17, 21, 32, 41, 30, 25, 52, 16, 39, 11, and 24.Find and interpret the range of their ages.Step 1: Locate the greatest and least number in the data set.Step 2: Subtract the least number from the greatest number.Step 3: Interpret the range of ages.

Key Idea #1 Quartiles _____________________________________________________________________________________________________________________________________________________________________________________________Data: 24, 36, 18, 30, 32, 37, 21, 31, 22, 28First, _____________________________________________________________

Next, _____________________________________________________________

Then, _____________________________________________________________

Key Idea #2 Interquartile range ____________________________________________________________________________________________________________________________________________________________________________________ 18, 21, 22, 24, 28, 30, 31, 32, 36, 37

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Finding the Interquartile Range

2) The dot plot shows the top speeds of 12 sports cars. Find and interpret the interquartile range of the data.

Check for Outliers 3)

Chapter 10 Data DisplaysDate: Lesson 10.4 Box-and-Whisker PlotsEssential Question

How can you use quartiles to represent data graphically?

Key IdeaBox-and Whisker Plot

A box-and-whisker plot __________________________________________________________________________________________________________________________________________________________________________________

The five numbers that make up the box-and-whisker plot are called the _____________________________________

Making a Box-and- Whisker Plot

1) The data shows how many hours each friend spent online last night. Make a box-and-whisker plot for the data. 1, 0, 2, 3, 4, 3, 6, 1, 0, 1, 2, 2

Step 1: Order the data. Find the median and the 1st and 3rd quartiles.

Step 2: Draw a number line atha includes the least and greatest values.

Step 3: Draw a box using the quartiles. Draw a line through the median. Draw whiskers fro the box to the least and greatest values.

Key Idea How data is distributed in a box-and-whisker plot:

Analyzing a Box-and- Whisker Plot

2) The box-and-whisker plot shows the body mass index (BMI) of a sixth grade class.

a) What fraction of the students have a BMI of at least 22?________________________________________________________________________________________________________________________________________________________________________________________________________________________

b) Are the data more spread out below the first quartile or above the third quartile?________________________________________________________________________________________________________________________________________________________________________________________________________________________

c) Find and interpret the interquartile range.________________________________________________________________________________________________________________________________________________________________________________________________________________________

Key Idea

Comparing Box-and- Whisker Plots

3) The double box-and-whisker plot represents the prices of snowboards at two stores.

a) Identify the shape of each distribution.________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________b) Which store’s prices are more spread out? Explain.________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________