Question

Suppose that y is directly proportional to x, and y = 150 when x = 15. What is the constant of proportionality?

Answer 1

Answer:  The required constant of proportionality is 10.

Step-by-step explanation:  Given that y is directly proportional to x, and y = 150 when x = 15.

We are to find the constant of proportionality.

According to the given information, we can write

$y\propto x\\\\\Rightarrow y=kx~~~~~~~~~~~~~~~~[\textup{where k is the constsnt of propotionality}].$

When y = 150 and x = 15, we get from the above equation that

$y=kx\\\\\Rightarrow 150=k\times15\\\\\Rightarrow k=\dfrac{150}{15}\\\\\Rightarrow k=10.$

Thus, the required constant of proportionality is 10.