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Finding the Fourth Proportional to 629.91, 869.11 and 393.49

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Solution

The fourth proportional to 629.91, 869.11 and 393.49 is: 542.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    629.91 : 869.11 = 393.49 : x
  2. Step 2: Convert to fraction form
    629.91/869.11 = 393.49/x
  3. Step 3: Cross multiply
    629.91x = 869.11 × 393.49
  4. Step 4: Simplify right side
    629.91x = 341,981.75
  5. Step 5: Solve for x
    x = 341,981.75/629.91
  6. Step 6: Final answer
    x = 542.91

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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.