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Finding the Fourth Proportional to 686.72, 947.95 and 477.20

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Solution

The fourth proportional to 686.72, 947.95 and 477.20 is: 658.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.72 : 947.95 = 477.20 : x
  2. Step 2: Convert to fraction form
    686.72/947.95 = 477.20/x
  3. Step 3: Cross multiply
    686.72x = 947.95 × 477.20
  4. Step 4: Simplify right side
    686.72x = 452,355.81
  5. Step 5: Solve for x
    x = 452,355.81/686.72
  6. Step 6: Final answer
    x = 658.72

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Double scale
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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.