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Finding the Fourth Proportional to 629.76, 869.12 and 397.12

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Solution

The fourth proportional to 629.76, 869.12 and 397.12 is: 548.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    629.76 : 869.12 = 397.12 : x
  2. Step 2: Convert to fraction form
    629.76/869.12 = 397.12/x
  3. Step 3: Cross multiply
    629.76x = 869.12 × 397.12
  4. Step 4: Simplify right side
    629.76x = 345,144.93
  5. Step 5: Solve for x
    x = 345,144.93/629.76
  6. Step 6: Final answer
    x = 548.06

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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.