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Question
Mr Leo earned $360 per week. Then her salary was increased to $420 per week. By what percent was her salary increased?

- Not sure but I did the following calculations anyways, because if I somewhat know how to do something, I try to learn and give the problems a shot.

- 420-360=60 [to get the difference between the salary increase]
- 60/420=14.3% [I actually am not really sure how to round these percentages because sometimes when I re-check my calculations backwards, it gives me another answer that is slightly off.

Answer
Very close. You basically have the right idea. The only change I would make is to divide 60 by 360, 60/360 = 16.7%, since you are calulating an increase from 360 to 420. A little subtle.

The other way around, if Ms. Leo's salary had dropped form 420 to 360 a week, then it would have dropped -60/420 = -14.3%.

Another way to represent this is to note that 420/360 = 1.167, which indicates an increase in 0.167 = 16.7%.

In the above, I have rounded off the percentage 16.666666 ... to 16.7. A rule of thumb is you round up if the next digit ≥ 5. Thus, 16.650000001 would be rounded up to 16.7 and 16.649999999 would be 16.6. For that matter, 16.6% would be rounded up to 17%.

Keep sending your work. You're getting better!

Randy

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randy patton

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college mathematics, applied math, advanced calculus, complex analysis, linear and abstract algebra, probability theory, signal processing, undergraduate physics, physical oceanography

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26 years as a professional scientist conducting academic quality research on mostly classified projects involving math/physics modeling and simulation, data analysis and signal processing, instrument development; often ocean related

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J. Physical Oceanography, 1984 "A Numerical Model for Low-Frequency Equatorial Dynamics", with M. Cane

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M.S. MIT Physical Oceanography, B.S. UC Berkeley Applied Math

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