Answer:
x = 25
Explanation:
We are given a word phrase:
In the proportion x over 5 equals 15 over 3 , which number is equal to x in the proportion?
So we will translate it to make it easier to solve.
Proportion x over 5 --->

equals ---> =
15 over 3 --->

Combining them, we get:

Solving this for x using cross multiplication:

Therefore, x = 25.