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Finding the Fourth Proportional to 520.78, 781.38 and 512.60

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Solution

The fourth proportional to 520.78, 781.38 and 512.60 is: 769.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    520.78 : 781.38 = 512.60 : x
  2. Step 2: Convert to fraction form
    520.78/781.38 = 512.60/x
  3. Step 3: Cross multiply
    520.78x = 781.38 × 512.60
  4. Step 4: Simplify right side
    520.78x = 400,535.39
  5. Step 5: Solve for x
    x = 400,535.39/520.78
  6. Step 6: Final answer
    x = 769.11

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.