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# Rates of Change

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Practice Rates of Change
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## Real World Applications – Algebra I

### Topic

How can we represent the earnings of a garment worker in Bangladesh?

### Student Exploration

In 2010, Bangladesh almost doubled the minimum monthly wage for all those that work in the garment industry. If your clothes come from H&M, Zara or Wal-Mart, it’s likely that your clothes were made by these workers. In 2010, their monthly wage was increased to $43 per month. This is a rate of change, since the units are dollars made per month. If we were to represent the amount made per day, we can represent the slope as follows: $\frac{43}{30 \ days}$, or $\frac{43}{30}$. If we were to put this into a calculator and divide, the number would be approximately 1.43. This means that a garment worker earns$1.43 per day. How much does this daily earning mean to you?

We can also use this rate of change to make predictions. Using either the fraction $\frac{43}{30}$ or 1.43, we can predict how much a garment worker makes in any amount of days. To find out how much this person works in 10 days, we multiply our rate of change with the number of days. In this case, $\left(\frac{43}{30}\right)\times 10 = 14.33$. How much does this person make in 50 days? 75 days? 100 days?

ANSWER: In 50 days, we just multiply $\frac{43}{30}\times 50$. We have$71.66. In 75 days we multiply $\frac{43}{30}$ by 75, which is$107.50. In 100 days, we have \$143.33 made.

### Extension Investigation

Find out how much someone close to you (like a parent) makes on a monthly paycheck. Find out how much this person would earn per day with the information you are given.

If you want to go a step further, you can even find out how much this person makes per hour! (You will have to either assume that this person works 8 hours a day or you will have to ask!)

If you want to go further with the garment worker example, find out how much this garment worker earns in an hour, assuming that this person works 8 hours a day.