Exercise 9 Page 65

We want to complete a table. We can use the portion where both values are known to find the missing values.

We know that we can earn 18 dollars when working 2 hours. Let's write this as a rate. 2hours/18dollars or 2/18We will use this rate to find the missing values.

First Value

We can find an equivalent rate with a denominator of 72 to find how many hours we need to work in order to earn 72 dollars.

Ratio 872 is equivalent to 218. This tells us that we need to work 8 hours to earn 72 dollars.

Second Value

Now we want to find how much we will earn when working 43 hours. It is better to use the rate 218= 19 to find this missing value, because we cannot easily multiply to make a numerator of 2 into a numerator of 43. 2/18=& 43/ ⇒ 2* ? = 4/3 [0.8em] 1/9=& 43/ ⇒ 1* ? = 4/3 We need to get an equivalent rate with a numerator of 43.

Ratio 4312 is also equivalent to 218. This means that we will earn 12 dollars when working 43 of an hour.