Final answer:
The slope of a straight line can be calculated by finding the rise over the run, or the change in the y-coordinates divided by the change in the x-coordinates. The slope value indicates the direction and steepness of the line.
Step-by-step explanation:
The slope of a straight line between two points can be calculated by finding the rise over the run. To calculate slope, designate one point as the starting point and the other point as the end point. Then, calculate the change in the y-coordinates (rise) divided by the change in the x-coordinates (run). For example, to find the slope of a line between two points representing altitudes of 4,000 meters and 6,000 meters, you would calculate the rise over run. The slope value tells you if the line is moving up or down the y-axis as the x-value increases, and how steep the line is.