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Finding the Fourth Proportional to 812.85, 1,217.45 and 487.55

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Solution

The fourth proportional to 812.85, 1,217.45 and 487.55 is: 730.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    812.85 : 1,217.45 = 487.55 : x
  2. Step 2: Convert to fraction form
    812.85/1,217.45 = 487.55/x
  3. Step 3: Cross multiply
    812.85x = 1,217.45 × 487.55
  4. Step 4: Simplify right side
    812.85x = 593,562.88
  5. Step 5: Solve for x
    x = 593,562.88/812.85
  6. Step 6: Final answer
    x = 730.22

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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.