The gradient (or slope) of a line can be calculated using the formula:

$m = \frac{y_2 - y_1}{x_2 - x_1}$

Here, we can see from the graph that one point on the line is $(3, -4)$. We can also assume that another point on the line passes through the origin, $(0, 0)$.

Using these two points, we apply the formula:

$m = \frac{-4 - 0}{3 - 0} = \frac{-4}{3}$

Thus, the gradient (slope) of the line is:

$m = -\frac{4}{3}$

Would you like any further details or explanations?

Here are 5 related questions to expand your understanding:

1. How would the slope change if the line passed through a different point?
2. What is the equation of the line in slope-intercept form using this slope?
3. How do you interpret a negative slope in terms of the line's direction?
4. Can you calculate the length of the line segment between two points on this line?
5. How would you find the x-intercept and y-intercept of this line?

Tip: The steeper the line, the larger the magnitude of the slope. Positive slopes rise from left to right, while negative slopes fall from left to right.