Section 3.3 ~ Graphics in the Media Introduction to Probability and Statistics Ms. Young ~ room 113

Objective Sec. 3.3 In this section, you will learn how to interpret more complex graphs that are commonly found in the media The graphs that we will look at are: Multiple bar graph Multiple line chart Stack plot Color coded map Contour map Three-dimensional graphs

Multiple Bar Graphs A multiple bar graph is an extension of a regular bar graph that compares two or more data sets  The data sets must have the same categories Sec. 3.3

Multiple Line Chart A multiple line chart is similar to a multiple bar graph, but shows the data sets using lines rather than bars Sec. 3.3

Example 1 Consider the stock, bond, and gold multiple line chart below. Suppose that, on July 7, you had invested $100 in a stock fund that tracks the S&P 500, $100 in a bond fund that follows the Lehman Index, and $100 in gold. If you sold all three funds on September 15, how much would you have gained or lost?  The stock fund was worth about $105 on Sept. 15 th, the bond fund about $99, and gold about $100  You would have gained about $4 on your total investment since the three together are worth $304 ( ), but your initial investment was $300 Sec. 3.3

Example 2 The figure below is a multiple bar graph of the numbers of U.S. households with computers and the number of on-line households. Redraw this graph as a multiple line chart. Sec. 3.3

Stack Plot A stack plot shows different data sets in a vertical stack  Can be stacked using bar charts or line charts More common to stack using line charts  The thickness of a wedge at any given time tells you the value at that time Sec. 3.3 The immigration rate to the U.S. from the Americas was about 4.6 million (5.9 – 1.3)

Example 3 The stack plot below shows death rates (deaths per 100,000 people) for four diseases since Based on this graph, what was the death rate for cardiovascular disease in 1980? Discuss the general trends visible on this graph. Sec. 3.3

Color-Coded Map Geographical data is data that corresponds to different geographical locations A color-coded map can be used to display geographical data  Created by color coding each category and using a basic map  Allows you to see geographical trends Sec. 3.3

Contour Map A contour map is used when data varies across geographical areas  Ex. ~ Temperatures across the U.S. over a particular time The contours connect areas that have the same temperatures Sec. 3.3

Three-Dimensional Graphs In some cases a graph is represented in 3-D to simply make it look nicer  Which means it is only representing two-dimensional data and a simple bar graph would represent the data the same way Other 3-D graphs are three-dimensional for a purpose  Each of the three axes carry distinct information Sec. 3.3

Combination Graphs Are complex graphs that contain a number of different types of graphs Sec. 3.3