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Finding the Fourth Proportional to 629.78, 869.49 and 405.82

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Solution

The fourth proportional to 629.78, 869.49 and 405.82 is: 560.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    629.78 : 869.49 = 405.82 : x
  2. Step 2: Convert to fraction form
    629.78/869.49 = 405.82/x
  3. Step 3: Cross multiply
    629.78x = 869.49 × 405.82
  4. Step 4: Simplify right side
    629.78x = 352,856.21
  5. Step 5: Solve for x
    x = 352,856.21/629.78
  6. Step 6: Final answer
    x = 560.28

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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.