9.4a Classwork (1)

Essential Question: How can you describe the spread of a data set?

1 Activity: Interpreting Statements

1. There are 24 students in your class. Your teacher makes the following statements:
· “The exam scores range from 75% to 96%.”
· “Most of the students received high scores.”

*If this and the next four questions are confusing, I complete them in the 9.4a Screencast - go watch it and come back.

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1a. What do you think the first statement means? Explain.

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1b. In the first statement, is your teacher describing the center of the data set? If not, what do you think your teacher is describing?

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1c. What do you think the scores are for most of the students in the class? Explain your reasoning.

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d. Use your teacher’s statements to make a dot plot that can represent the distribution of the exam scores of the class.

2 Activity: Grouping Data

The numbers of U.S. states visited by each student in a sixth grade class are shown.

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a. Between what values do the data range?

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b. Find the median. How many values are greater than the median? How many are less than the median?

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c. Find the median (first quartile) of the numbers less than the proper median and then find the median (third quartile) of the numbers below the proper median. (I did half of this problem for you)

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d. Into how many parts did you divide the data set? How many data values are in each part?

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e. Graph the median and the values you found in parts (a) and (c) on a number line. Are the distances the same between these points?

3 Activity: Adding a Value to a Data Set

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A new student joins the class in Activity 2. The new student has visited 41 states. How does adding this value affect the values on your number line in part (e) of Activity 2?

4 Activity: Analyzing Data Sets

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Essential Question: How can you describe the spread of a data set?

1a. What do you think the first statement means? Explain.

1b. In the first statement, is your teacher describing the center of the data set? If not, what do you think your teacher is describing?

1c. What do you think the scores are for most of the students in the class? Explain your reasoning.

d. Use your teacher’s statements to make a dot plot that can represent the distribution of the exam scores of the class.

a. Between what values do the data range?

b. Find the median. How many values are greater than the median? How many are less than the median?

c. Find the median (first quartile) of the numbers less than the proper median and then find the median (third quartile) of the numbers below the proper median. (I did half of this problem for you)

d. Into how many parts did you divide the data set? How many data values are in each part?

e. Graph the median and the values you found in parts (a) and (c) on a number line. Are the distances the same between these points?

A new student joins the class in Activity 2. The new student has visited 41 states. How does adding this value affect the values on your number line in part (e) of Activity 2?

Identify and circle the data set that is the least spread out and the data set that is the most spread out.