Answer:
k = 4/25 or 0.16
Explanation:
Given the following data;
y = 4/5
x = 5
To find the variation constant, k;
y is directly proportional to x
Mathematically, y = kx
Substituting into the formula, we have;
4/5 = k5
Cross-multiplying, we have;
4 = 25k
k = 4/25