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Finding the Fourth Proportional to 520.57, 780.78 and 135.82

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Solution

The fourth proportional to 520.57, 780.78 and 135.82 is: 203.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    520.57 : 780.78 = 135.82 : x
  2. Step 2: Convert to fraction form
    520.57/780.78 = 135.82/x
  3. Step 3: Cross multiply
    520.57x = 780.78 × 135.82
  4. Step 4: Simplify right side
    520.57x = 106,041.64
  5. Step 5: Solve for x
    x = 106,041.64/520.57
  6. Step 6: Final answer
    x = 203.70

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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.