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
[tex]y\propto x\\\\\Rightarrow y=kx~~~~~~~~~~~~~~~~[\textup{where k is the constsnt of propotionality}].[/tex]
When y = 150 and x = 15, we get from the above equation that
[tex]y=kx\\\\\Rightarrow 150=k\times15\\\\\Rightarrow k=\dfrac{150}{15}\\\\\Rightarrow k=10.[/tex]
Thus, the required constant of proportionality is 10.
