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Finding the Fourth Proportional to 688.38, 949.24 and 478.78

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Solution

The fourth proportional to 688.38, 949.24 and 478.78 is: 660.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    688.38 : 949.24 = 478.78 : x
  2. Step 2: Convert to fraction form
    688.38/949.24 = 478.78/x
  3. Step 3: Cross multiply
    688.38x = 949.24 × 478.78
  4. Step 4: Simplify right side
    688.38x = 454,477.13
  5. Step 5: Solve for x
    x = 454,477.13/688.38
  6. Step 6: Final answer
    x = 660.21

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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.