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Determine, to the nearest whole percent, the percent of change of 186 dollars and 40 cents to 235 dollars.
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State whether it is an increase or a decrease.
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A percentage of change is equal to the amount of change divided by the original amount multiplied by 100.
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The first part of this calculation gives a proportion of the original amount that the change represents.
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The second part converts this from a decimal to a percentage.
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Let’s look at the values in this question.
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The original, or starting, amount is equal to 186 dollars and 40 cents.
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The amount of change is equal to 235 dollars minus 186 dollars and 40 cents, which is 48 dollars and 60 cents.
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Now, let’s substitute these values into the formula.
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The percent of change is equal to 48 dollars and 60 cents divided by 186 dollars and 40 cents multiplied by 100.
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The question states that our answer should be given to the nearest whole percent.
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We’ll suggest we can use a calculator to evaluate this.
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It’s equal to 26.072961.
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Rounded to the nearest whole percent, this is equal to 26 percent.
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The second part of the question is actually more straightforward.
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It asked whether this is an increase or a decrease.
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Well, as the change is from 186 dollars and 40 cents to 235 dollars, this is an increase.
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Now, there is one commonly-made error that you need to watch out for.
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Remember, in the formula for percent of change, we need to divide by the original amount.
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The common error is to accidentally divide by the new amount instead.
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In this question, this will give a calculation of 48.60 divided by 235 multiplied by 100.
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And to the nearest whole percent, this would be 21 percent.
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This is an incorrect answer.
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But if you did get 21 percent yourself, then this is where you’re going wrong.
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Remember, when calculating a percent of change, we always divide by the original amount.