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Finding the Fourth Proportional to 520.38, 780.57 and 405.06

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Solution

The fourth proportional to 520.38, 780.57 and 405.06 is: 607.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    520.38 : 780.57 = 405.06 : x
  2. Step 2: Convert to fraction form
    520.38/780.57 = 405.06/x
  3. Step 3: Cross multiply
    520.38x = 780.57 × 405.06
  4. Step 4: Simplify right side
    520.38x = 316,177.68
  5. Step 5: Solve for x
    x = 316,177.68/520.38
  6. Step 6: Final answer
    x = 607.59

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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.