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Finding the Fourth Proportional to 520.17, 780.23 and 211.86

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Solution

The fourth proportional to 520.17, 780.23 and 211.86 is: 317.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    520.17 : 780.23 = 211.86 : x
  2. Step 2: Convert to fraction form
    520.17/780.23 = 211.86/x
  3. Step 3: Cross multiply
    520.17x = 780.23 × 211.86
  4. Step 4: Simplify right side
    520.17x = 165,298.47
  5. Step 5: Solve for x
    x = 165,298.47/520.17
  6. Step 6: Final answer
    x = 317.78

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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.