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Finding the Fourth Proportional to 520.91, 781.17 and 212.59

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Solution

The fourth proportional to 520.91, 781.17 and 212.59 is: 318.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    520.91 : 781.17 = 212.59 : x
  2. Step 2: Convert to fraction form
    520.91/781.17 = 212.59/x
  3. Step 3: Cross multiply
    520.91x = 781.17 × 212.59
  4. Step 4: Simplify right side
    520.91x = 166,070.12
  5. Step 5: Solve for x
    x = 166,070.12/520.91
  6. Step 6: Final answer
    x = 318.81

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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.