Module 8 Lesson 2: Statistical Variability and Comparing Pop

Mod 8 Lsn 2: Statistical Variability and Comparing Populations

Math 7 - Mr. Miller

You must read through lesson 2, before completing this assignment

Make sure to watch the videos on page 2 and 3 of the lesson

Vocabulary you should know:

• Mean - also called the average of a set of numbers. To find the mean (average) add up all the numbers and divide by how many numbers there are in the set.

• Mean Absolute Deviation (MAD) - The average distance of each data point from the mean (average). View the video on page 3 of lesson 2 for a good explanation of how to find the MAD.

• Variability - describes how the data points are spread out from the average

• Range - the distance between the smallest and largest data points

Multiple Choice

A sample should be...

• representative of middle school students only

• a very large group

• representative of the population

• representative of people who volunteer

Multiple Choice

Anthony opened a new store and wants to conduct a survey to determine the best store hours. Which is the best representative sample?

• A group of randomly selected people who visit his website on one night.

• The first 20 people who walk into his store one day.

• A group of randomly selected people who come to the store in one week.

• Every person he meets at his health club one night.

Multiple Choice

Terry made the dot plot above to chart the amount of time, in minutes, that it took students to eat breakfast in the morning. How many students took 5 or more minutes to eat their breakfast?

• 11

• 12

• 16

• 14

Multiple Choice

Another word for mean is...

• Sum

• Average

• Product

• Equation

Multiple Choice

To find the mean (average) of a set of numbers you...

• multiply all the numbers then divide by how many numbers are in the set

• add the numbers together, then divide by how many numbers are in the set

Multiple Choice

Find the mean of these numbers: 2, 57, 38, 42, 6

• 29

• 50

• 38

• 145

Multiple Choice

The height of three basketball players is 210 cm, 220 cm and 191 cm.

What is their average height?

• 210

• 207

• 220

• 200

What does the Mean Standard Deviation (MAD) tell us about a data set?

• It indicates how spread out the data is from the mean (average)

• A small MAD number means that the data points are close to each other. For example, the set 1,2,3,4 has a MAD value of 1. This means the data points are close together - less variability in the data set

• A large MAD number means the data points are more spread out. For example, the set 1, 20, 100, 300 has a MAD value of 114.75. This high number means that the data is not close together and is spread out - more variability in the data set

Multiple Choice

What is Mean Absolute Deviation?

• The mean of the data

• The absolute value of the mean

• The variation of data values around the mode

• The average distance between the data values and the mean

Multiple Choice

What is the first step when calculating the Mean Absolute Deviation?

• Find the distance each value is from 0

• Find the mean of the distances

• Find the mean of the data

Multiple Choice

What is the second step when calculating the Mean Absolute Deviation?

• Subtract the mean calculated from step 1 from each data point.

• multiply the mean by each data point

Multiple Choice

What is the third step when calculating the Mean Absolute Deviation?

• Find the blue light special at Kmart

• Find the average of the differences (deviations) found in step 2

Multiple Choice

Find the Mean Absolute Deviation (MAD) of the following data points:

10, 9, 3, 8, 10.

• 3

• 1

• 5

• 2

Multiple Choice

Find the Mean Absolute Deviation (MAD): 5, 11, 2, 7, 16. The Mean is 8.2

• 3.2

• 1.2

• 2.8

• 4.2

Multiple Choice

Find the Mean Absolute Deviation (MAD) of the following data points: 58, 38, 54, 48, 26, 36

• 43

• 10

• 20

• 12

Multiple Choice

Which mean absolute deviation would have a greater variability or spread? 4.2 or 8.5?

• 4.2

• 8.5

Range

• Tells us how spread out the data is

• To find the range subtract the smallest number from the largest

• For Example: Fred's score on five tests were 60, 95, 100, 85 75. To find his range of scores subtract the smallest number from the largest 100-60 = 40. The number 40 is the range of his scores.

• Gives us a basic idea of how spread out the data is, to get a more precise calculation for variability we would need to find the MAD.

Multiple Choice

The range is found by finding the _______________ number and subtracting the ________________ number.

• smallest, biggest

• even, odd

• biggest, smallest

• middle, first

Multiple Choice

Find the range of the following numbers: 67, 95, 99, 102, 98, 74, 98

• 102

• 98

• 35

• 67

Multiple Choice

What is the range of this data set? 93, 100, 82, 93, 67, 100, 67, 82, 93, 93

• 100

• 67

• 33

• 50