Question

Denmark uses the kroner as its currency. Before a trip to Denmark, Mia wants to exchange $1,700 for kroner. Does Bank A or Bank B have a better exchange rate? Explain

Answer 1

Let x be the dollars and y be the Kroners

A proportional relationship is given by

`y=kx`

Where k is the constant of proportionality.

We need to find out k for both banks A and B.

Exchange rate of Bank A:

As you can see from the table, 408 Kroners for $80

`\begin{gathered} y=kx \\ k=(y)/(x)=(408)/(80)=5.1 \end{gathered}`

So, the exchange rate of Bank A is 5.1

`y=kx=5.1\cdot1700=8670`

This means that Bank A will give you 8670 Kroners in exchange for $1700.

Exchange rate of Bank B:

From the given graph, locate any one x, y point

Let us select x = 10 and y = 50

`\begin{gathered} y=kx \\ k=(y)/(x)=(50)/(10)=5 \end{gathered}`

So, the exchange rate of Bank B is 5

`y=kx=5\cdot1700=8500`

This means that Bank B will give you 8500 Kroners in exchange for $1700.

As you can see, Bank A has a better exchange rate and would give Mia more Kroners.