Describing Measures of Center and Variability

Which class was more consistent in their Algebra Scores?

• Class #2

• Class #1

• Both classes had the same consistency.

• 50%

The double line plot shows the number of students who attended the home games of the baseball team for two recent seasons.  Which of the following statements is NOT true.

• The median attendance for 2009 was less than the median attendance than 2010.

• The attendance for 2010 was more consistent, so the MAD would be smaller than the MAD for 2009.

• The attendance for 2009 was more consistent, so the MAD would be smaller than the MAD for 2010.

• The attendance for 2010 ranged from 20-27.

For which group of data does the mean equal the mode?

• 4, 5, 5, 8

• 4, 4, 6, 6

• 4, 5, 6, 6

• 4, 5, 5, 6

You are given a list of numbers with a median of 10.  Each of the numbers is doubled.  What will happen to the median of the second set of numbers?

• It will increase by one-half

• It will double

• It will stay the same

• Not enough information is given

The list below shows the number of words per minute students in Mrs. DeFelice's class typed last week:
42, 55 ,62, 39, 38, 70, 54, 56, 73.
Which would change the range from 35 to 38?

• A new student types 38 wpm

• The student that  typed 39 wpm moved

• A new student types 35 wpm

• The student that typed 73 wpm movedd

Here are the times (in minutes) that six students needed to finish a quiz:
10, 14, 15, 15, 14, 10
The Mean Absolute Deviation for this data is 2.
A seventh student took 8 minutes to finish the quiz.  We added his time to our data.  What will happen to the MAD?

• It will decrease because our range is bigger.

• It will increase because our range is bigger.

• It will not change.

• It will decrease because we have more numbers in our data set.

A data set consists of the numbers 2, 2, 5, 6 and 15.  Which statement is true for this data?

• median > mean

• mean = mode

• mode < median

• median = mode

Which is true?

• Mean < Median

• Mean = Median

• Mean > Median

Which measure of variability should you use?

• IQR

• standard deviation