Question

The variable Z is directly proportional to X. when X is 15, Z has the value of 45. what is the value of Z when X=23

Answer 1

$If\ Z\ is\ directly\ proportional\ to\ X\ then\ \frac{Z}{X}=const.\\------------------------\\X=15\ and\ Z=45\\\\X=23\ and\ Z=?\\\\\frac{Z}{23}=\frac{45}{15}\to\frac{Z}{23}=3\ \ \ \ |multiply\ both\ sides\ by\ 23\\\\\huge\boxed{Z=69}$