Question

how many killer whales are there when there are 5 million beluga whales

Answer 1

We know that the number of og beluga whales varies directly as the number of killer whales, that means that we can write a relation of the form:

$y=kx$

where y is the number of beluga whales, x is the number of killer whales and k is the constant of proportionality.

To answer the question we first need to find k, to do that we plug the values x=23 and y=14 in the equation above and solve for k:

$\begin{gathered} 14=k23 \\ k=\frac{14}{23} \end{gathered}$

Now that we know k the relation is:

$y=\frac{14}{23}x$

Finally to find the number of killer whales if there are 5 millions of beluga whales we plug y=5 in the equation above and solve for x:

$\begin{gathered} 5=\frac{14}{23}x \\ x=\frac{5\cdot23}{14} \\ x=8.21 \end{gathered}$

Therefore when there are 5 millions beluga whales we have 8.21 millions of killer whales.