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Finding the Fourth Proportional to 685.05, 939.20 and 672.75

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Solution

The fourth proportional to 685.05, 939.20 and 672.75 is: 922.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.05 : 939.20 = 672.75 : x
  2. Step 2: Convert to fraction form
    685.05/939.20 = 672.75/x
  3. Step 3: Cross multiply
    685.05x = 939.20 × 672.75
  4. Step 4: Simplify right side
    685.05x = 631,843.44
  5. Step 5: Solve for x
    x = 631,843.44/685.05
  6. Step 6: Final answer
    x = 922.34

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Double scale
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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.