Q 15. - The Practice of Statistics for AP

Question

Buying music online Young people are more likely than older folk to buy music online. Here are the percent's of people in several age groups who bought music online in $2006$:

(a) Explain why it is not correct to use a pie chart to display these data.

(b) Make a bar graph of the data. Be sure to label your axes and title your graph. 

Step-by-Step Solution

Answer

Part (a) It is not appropriate because there is not$100\%$ data is present.

Part (b) The bar chart is 

Part (a) Step 1: Given Information

The percentage of buying music online based on the age group is- 

Age group	Brought music online
12-17 years	24%
18-24 years	21%
25-34 years	20%
35-44 years	16%
45-54 years	1%
55-64 years	3%
65 years and over	1%

Part (a) Step 2: Concept

The distribution of a category variable is displayed using pie charts and bar graphs. Any set of quantities measured in the same units can be compared using bar graphs. It's a good idea to ask yourself, "What do I see?" when looking at any graph.

Part (a) Step 3: Calculation

A pie chart is a form of a graph that uses slices to illustrate the relative size of the data being presented. The sum of the percentages must equal $100$ percent in order to create the pie chart.

The sum of percentages in this case is:

Sum of percentages= $(24 + 21 + 20 + 16 + 10 + 3 + 1) \% = 95\%$

Because the total does not equal $100$ percent. As a result, a pie chart is inappropriate in this situation.

Part (b) Step 1: Explanation

The bar chart can be constructed as: