1. Example 2.7 Relationship Between Salaries and Domestic Gross for Movie Stars Analyzing Relationships with Scatterplots

2. 2.12.1 | 2.2 | 2.3 | 2.4 | 2.5 | 2.6 | 2.8 | 2.9 | 2.10 | 2.11 | 2.122.22.32.42.52.62.82.92.102.112.12 Objective To use StatPro’s scatterplot procedure to illustrate the relationship between movie gross and actor salary.

3. 2.12.1 | 2.2 | 2.3 | 2.4 | 2.5 | 2.6 | 2.8 | 2.9 | 2.10 | 2.11 | 2.122.22.32.42.52.62.82.92.102.112.12 ACTORS.XLS n Recall that this data set contains information on 66 movie stars including their, Gender, Domestic Gross, Foreign Gross and Salary. n The data may lead us to suppose that stars whose movies gross large amounts have the largest salaries. Is this true?

4. 2.12.1 | 2.2 | 2.3 | 2.4 | 2.5 | 2.6 | 2.8 | 2.9 | 2.10 | 2.11 | 2.122.22.32.42.52.62.82.92.102.112.12 Scatterplots n We are often interested in the relationship between two variables. n A useful way to picture this relationship is to plot a point for each observation, where the coordinates of the point represent the values of the two variables. n The resulting graph is a scatterplot.

5. 2.12.1 | 2.2 | 2.3 | 2.4 | 2.5 | 2.6 | 2.8 | 2.9 | 2.10 | 2.11 | 2.122.22.32.42.52.62.82.92.102.112.12 Scatterplots -- continued n After constructing a scatterplot, we can examine the scatter of points. n We can usually see whether there is any relationship between the two variables, and, if so, what type of relationship it is. n We will use a scatterplot to determine if the statement about the relationship between movie gross and salaries is true.

6. 2.12.1 | 2.2 | 2.3 | 2.4 | 2.5 | 2.6 | 2.8 | 2.9 | 2.10 | 2.11 | 2.122.22.32.42.52.62.82.92.102.112.12 Creating a Scatterplot n To analyze this we need to plot each star’s salary on the vertical axis and the corresponding domestic gross on the horizontal axis. n To create this scatterplot: – Place the cursor anywhere in the data set. – Select the StatPro/Charts/Scatterplot menu item. – Select Salary as the Y variable, Domestic Gross as the X variable and give the chart sheet a name such as Scatter.

7. 2.12.1 | 2.2 | 2.3 | 2.4 | 2.5 | 2.6 | 2.8 | 2.9 | 2.10 | 2.11 | 2.122.22.32.42.52.62.82.92.102.112.12 The Resulting Scatterplot

8. 2.12.1 | 2.2 | 2.3 | 2.4 | 2.5 | 2.6 | 2.8 | 2.9 | 2.10 | 2.11 | 2.122.22.32.42.52.62.82.92.102.112.12 Analyzing the Scatterplot n The message is clear. The points tend to move up and to the right. This means that stars in films with large domestic grosses tend to make the largest salaries. n The correlation of 0.61 shown in the chart supports this conclusion. As we will see in Chapter 3, this implies a reasonably strong positive linear relationship between the two variables.