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Finding the Fourth Proportional to 997.20, 1,375.32 and 647.28

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Solution

The fourth proportional to 997.20, 1,375.32 and 647.28 is: 892.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    997.20 : 1,375.32 = 647.28 : x
  2. Step 2: Convert to fraction form
    997.20/1,375.32 = 647.28/x
  3. Step 3: Cross multiply
    997.20x = 1,375.32 × 647.28
  4. Step 4: Simplify right side
    997.20x = 890,217.13
  5. Step 5: Solve for x
    x = 890,217.13/997.20
  6. Step 6: Final answer
    x = 892.72

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.