Is y varies directly as x, and y is 18 when x is 5 witch expression can be used to find the value of y when x is 11?

As the variation is direct we have:
 
 Where,
 k: proportionality constant
 We must find the value of k.
 For this we use the following data:
 y is 18 when x is 5.
 Substituting values we have:
 
 From here, let's clear k:
 
 Then, replacing values we have:
 
 For x = 11 we have:
 
 
 An expression that can be used to find the value of y when x is 11 is:
 
 When x = 11 we have:
 

Hdbhebdbshshhsiwbsj ishdhjabrht. tiehwoejh utgv ha j. event