Final answer:
The value of the y-intercept is -7/10.
Step-by-step explanation:
The equation of a line can be written in the form y = mx + b, where m represents the slope and b represents the y-intercept.
Given that the slope of the line is 1/4, we can write the equation as y = (1/4)x + b.
We are also given that the line passes through the point (0.4, -1/2). Substituting these values into the equation, we have -1/2 = (1/4)(0.4) + b.
Simplifying, we find that b = -1/2 - 1/10 = -6/10 - 1/10 = -7/10.
Therefore, the value of the y-intercept is -7/10.