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Finding the Fourth Proportional to 629.92, 869.20 and 397

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Solution

The fourth proportional to 629.92, 869.20 and 397 is: 547.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    629.92 : 869.20 = 397 : x
  2. Step 2: Convert to fraction form
    629.92/869.20 = 397/x
  3. Step 3: Cross multiply
    629.92x = 869.20 × 397
  4. Step 4: Simplify right side
    629.92x = 345,072.40
  5. Step 5: Solve for x
    x = 345,072.40/629.92
  6. Step 6: Final answer
    x = 547.80

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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.