the required value of y at x = 4 is 16.64.
Given that,
y varies directly as the cube of x. When x = 3, then y = 7.To determine the y when x = 4.
What is proportionality?
Proportionality is defined as between two or more sets of values, and how these values are related to each other in the sense that are they directly proportional or inversely proportional to each other.
Here,
y is directly proportional to the cube of x i.e
y ∝ x³
y = kx³ - - - - - (1)
where k is proportionality constant,
At x = 3 y = 7
7 = k (3)³
7 / 27 = k
k = 0.26
Put k in equation 1
y = 0.26 x³
Now at x = 4
y = 0.26 * 4³
y = 0.26 * 64
y = 16.64
Thus, the required value of y at x = 4 is 16.64.
Learn more about proportionality here: https://brainly.com/question/22620356
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