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3D and higher
Browse Middle School Ratio/Proportion
Stars indicate particularly interesting answers or
good places to begin browsing.
Selected answers to common questions:
Unit conversions, unit cancellation.
What is a ratio?
- Using Estimation to Check Your Answer [03/28/2008]
I had to find the percent increase in population from 38,000,000 to
515,000,000 and I got 1,255%. But that seems way too big. Where am I
- Using Scale Drawings [05/24/2002]
Use a scale drawing to determine the actual size of an object.
- Variation on Combined Work [06/13/2002]
If you run a large pipe for 4 hours, and run a small pipe for 9 hours,
you can fill 1/2 a pool. If you run both pipes together for 12 hours,
you can fill the whole pool. How long would it take to fill the pool
using each pipe by itself?
- Visualizing Ratios to Scale Least Common Multiples [10/02/2010]
The ratio of Cotsworld sheep to Swaledales is 3:5, and the
ratio of Swaledales to Longwools is 7:4. What is the ratio
of Cotsworlds to Longwools?
- Weighted Averages [11/30/2001]
An advertisement for an orange drink claims that the drink contains 10%
orange juice. How much pure orange juice would have to be added to 5
quarts of the drink to obtain a mixture containing 40% orange juice?
- Which is More? [05/21/2002]
Given a choice between nickels stacked to your height, or quarters
placed end to end to your height, which should you choose?
- Why Does Cross Multiplication Work? [05/09/2002]
Why does the rule a/b = c/d also mean ad = bc? Why can we solve
proportions by cross multiplying?
- Why There are 12 Tones in a Scale [12/28/2000]
Why are there 12 tones in an octave? Can you explain the significance or
the equation r^n = 2^m? Also, what's so special about a fifth? Why should
the scale be based on the fraction 3/2?
- Working with Multi-Part Ratios [05/21/2007]
Can you explain how to work with a three-part ratio such as 2:3:6? I
understand basic ratios but am not sure how the various numbers relate
to each other when there are more than two of them.
- Writing Ratios [06/03/1999]
How can I write a ratio in three different ways?
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