In an increasingly data-driven world, it is more important than ever for students as well as professionals to better understand basic statistical concepts. 100 Questions (and Answers) About Statistics addresses the essential questions that students ask about statistics in a concise and accessible way. It is perfect for instructors, students, and practitioners as a supplement to more comprehensive materials, or as a desk reference with quick answers to the most frequently asked questions.

# How Can Scatter Charts Help Me Understand Correlation Coefficients?

### How Can Scatter Charts Help Me Understand Correlation Coefficients?

As you learned earlier, a scatter chart is a visual representation of two data points for each case. Creating a scatter chart is simply a matter of placing coordinates on an X-Y grid, such as you see in Figure 43.1 for the following data.

Participant

Height (inches)

Weight (pounds)

1

66

154

2

54

123

3

71

214

4

65

265

5

74

276

6

61

205

7

52

116

8

73

245

9

78

235

10

59

156

### Figure 43.1 A scatter chart showing a positive correlation

When you look at Figure 43.1, you can see that the data points are organized from the lower left-hand corner of the chart to the upper right-hand corner. This arrangement indicates that the slope of these points is positive as is the correlation between the variables (it is actually .81). Figure 43.1 is a visual representation of a positive correlation. As ...