Day 3 – Measures of Central Tendency

Outlier: Range:

Measure of Central Tendency Procedure When to Use

Mean

Median

Mode

1. Bowling:

a. What are the mean, median, mode and range of the bowling scores. b. Which measure of central tendency best describes the scores? Why? c. What effect does the score of 189 have on the measures of central tendency for this data set? Mean? Median? Mode? d. Consider the scores from the previous question without the score of 189 for Bowler 5. What are the mean, median, mode, and range of the scores?

2. Your grades on three exams are 80, 93 and 91. What grade do you need on the next exam to have an average of 90 on the four exams?

Part II: Box and whisker plot

Brain Break: Penny Activity Let’s make one!

1. The table below shows the number of crops harvested in the U.S. for a certain period. Draw a box and whisker plot to represent the data.

5 Number Summary:

Interquartile Range: The different between the third and first quartiles. The box represents 50% of the data. THE BOX SHOULD LEAVE OUT THE OUTLIERS???? YES – OUTLIERS ARE DRAWN AS ASTERICS

IQR – the difference between Q3 and Q1

2. The table shows the number of sales by 8 sales people over the past month. Draw a box and whisker plot to represent the data.

5 Number Summary:

3. The finishing times of two runners for several one-mile races, in minutes, are shown in the box-and-whisker plots.

a. Who has the faster median time? __________

b. Who has the slowest time? _______________

c. Overall, who is the faster runner? Explain.

Sales-person

#of Sales

Nancy 11

Carlos 3

Orlando 8

Russell 12

Betty 16

Misty 5

Carmen 14

Ruiling 9