CK-12 Probability and Statistics - Advanced

http://www.ck12.org Chapter 2. Visualizations of Data

TABLE2.3: Frequency table using tally marks

Number of Plastic

Beverage Bottles

per Week

Tally Frequency

1 | 1

2 | 1

3 ||| 3

4 |||| 4

(^5) @|||||@ 6
(^6) @|||||||@ 8
7 @||||||@ 7
8 || 2
This data set could almost be considered categorical and was easy to translate into a frequency table. In many
situations, you will need to create your own categories, or classifications. The following data set shows the countries
in the world that consume the most bottled water per person per year.
TABLE2.4:
Country Liters of Bottled
Water Consumed per
Person per Year
Italy 183. 6
Mexico 168. 5
United Arab Emirates 163. 5
Belgium and Luxembourg 148. 0
France 141. 6
Spain 136. 7
Germany 124. 9
Lebanon 101. 4
Switzerland 99. 6
Cyprus 92. 0
United States 90. 5
Saudi Arabia 87. 8
Czech Republic 87. 1
Austria 82. 1
Portugal 80. 3
Figure:Bottled Water Consumption per Person in Leading Countries in 2004.Source:http://www.earth-policy.org/
Updates/2006/Update51_data.htm
This data has been measured at the ratio level (see levels of measurement in chapter one), so there is some flexibility
required in order to create meaningful and useful categories for a frequency table. The values range from 80.3 liters,
up to 183 liters. By examining the data, it might seem appropriate for us to create frequency table by 10s (80s,90s,
etc.) We will skip the tally marks in this case because the data is already in numerical order and it is easy to see how
many are in each classification.
TABLE2.5:
Liters per Person Frequency
[ 80 − 90 ) 4
[ 90 − 100 ) 3