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Finding the Fourth Proportional to 520.61, 781.26 and 478.90

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Solution

The fourth proportional to 520.61, 781.26 and 478.90 is: 718.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    520.61 : 781.26 = 478.90 : x
  2. Step 2: Convert to fraction form
    520.61/781.26 = 478.90/x
  3. Step 3: Cross multiply
    520.61x = 781.26 × 478.90
  4. Step 4: Simplify right side
    520.61x = 374,139.11
  5. Step 5: Solve for x
    x = 374,139.11/520.61
  6. Step 6: Final answer
    x = 718.66

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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.