Final answer:
The slope of line c, which is parallel to line b, is 0.8. This is calculated using the formula for slope (change in y over change in x) between two points that line b passes through.
Step-by-step explanation:
To find the slope of a line that is parallel to another, we need to understand that parallel lines have the same slope. The given line b passes through points (1, 4) and (6, 8). To calculate the slope of line b, you use the formula:
slope (m) = (change in y) / (change in x) = (y2 - y1) / (x2 - x1)
So for line b:
m = (8 - 4) / (6 - 1) = 4 / 5 = 0.8
Since line c is parallel to line b, it will have the same slope. Therefore, the slope of line c is also 0.8.