Mean Absolute Deviation

After surveying 10 friends about the number of people in their households, Jack got the following answers:

1,6,2,4,4,3,5,5,2,8

What is the mean number of people per household?

Type only the number.

After surveying 10 friends about the number of people in their households, Jack got the following answers:

1,6,2,4,4,3,5,5,2,8

Calculate the MAD of the number of people per household.

Type only the number.

The teachers are trying a new method to make their scores on a standardized test less variable.

The scores before the method were:

76, 81, 85, 79, 89, 86, 84, 80, 88, 79

The scores after the method were:

79, 82, 84, 82, 77, 85, 82, 80, 78, 83

What is the mean of the BEFORE test scores?

The teachers are trying a new method to make their scores on a standardized test less variable.

The scores before the method were:

76, 81, 85, 79, 89, 86, 84, 80, 88, 79

The scores after the method were:

79, 82, 84, 82, 77, 85, 82, 80, 78, 83

What is the M.A.D. of the BEFORE test scores?

The teachers are trying a new method to make their scores on a standardized test less variable.

The scores before the method were:

76, 81, 85, 79, 89, 86, 84, 80, 88, 79

The scores after the method were:

79, 82, 84, 82, 77, 85, 82, 80, 78, 83

What is the mean of the AFTER test scores?

The teachers are trying a new method to make their scores on a standardized test less variable.

The scores before the method were:

76, 81, 85, 79, 89, 86, 84, 80, 88, 79

The scores after the method were:

79, 82, 84, 82, 77, 85, 82, 80, 78, 83

What is the M.A.D. of the AFTER test scores?

Use the M.A.D. from the before and after data to answer the following question:

Did the teachers reach their goal of making the scores less variable?

• Yes. They were less variable.

• No. They were just as variable.

• No. They were more variable.

• Yes. The mean score went up.

• No. The mean score went down.