Answer: 0.53
Explanation:
From variation ,
y ∞ x ------------------------------------------------1
y = kx , where k is called the constants of proportionality and must be calculated first before proceeding.
substitute for the values in equation 2 ,below
y = kx -----------------------------------------------2
16 = k2.1
k = 16/2.1
Now to find the value of x, make x the subject of the formula in equation 2
x = y/k
= 4/ 16/2.1
= 4 ÷ 16/2.1
= 4 x 2.1/16
= 2.1/4
= 0.525
≅ 0.53