Find the constant of variation k. yvaries directly with x; y=400 when x=1000
y = k x
400 = k * 1000
Solve for k
To find the constant of variation (k) when y varies directly with x, we can use the formula:
y = k * x
We are given that y is 400 when x is 1000. Using these values, we can substitute them into the formula and solve for k.
400 = k * 1000
To solve for k, divide both sides of the equation by 1000:
400/1000 = k
0.4 = k
Therefore, the constant of variation (k) is 0.4.