When rounded to the nearest thousand and elephant weight is 5,000 pounds. What is the least amount the elephant could weigh?

4500

Step-by-step explanation:

As long as your number isn't less than 500, it will always round up.

Okay, so y = kx where k is the constant of proportionality. 
Just plug in the values...the time affects the number of tables, so it must be the independent variable, or x value. 

5 = 15k

Divide both sides by 15, and you are left with 1/3. This is the constant of proportionality.