Recognize and interpret linear, semilog, and log-log scales and calculate slopes from data found in figures, graphs, and tables

Calculating Slope

Slope (m) is a characteristic of a linear relationship.

m = (y2 - y1) / (x2 - x1)

Conceptually, slope is "rise over run", representing the change in value on the y-axis that corresponds to a change in value on the x-axis for two data points, (x₁, y₁) and (x₂, y₂) above where x₂ is greater than x₁. A positive slope indicates that the value represented on the y-axis will increase with an increase in value on the x-axis, while a negative slope indicates the y-axis value will decrease with an increase in the x-axis value.