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Finding the Fourth Proportional to 520.56, 780.84 and 439.92

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Solution

The fourth proportional to 520.56, 780.84 and 439.92 is: 659.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    520.56 : 780.84 = 439.92 : x
  2. Step 2: Convert to fraction form
    520.56/780.84 = 439.92/x
  3. Step 3: Cross multiply
    520.56x = 780.84 × 439.92
  4. Step 4: Simplify right side
    520.56x = 343,507.13
  5. Step 5: Solve for x
    x = 343,507.13/520.56
  6. Step 6: Final answer
    x = 659.88

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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.