Answer: 5 1/4
Step-by-step explanation:
We use the formula for direct proportion to solve the question since we are informed that y varies directly with x and that y is 84 when x is 16.
The formula will be:
y = kx
where,
y = 84
x = 16
We then slot the values into the formula
y = kx
84 = 16k
k = 84/16
k = 5 1/4
The constant of proportionality is 5 1/4