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Finding the Fourth Proportional to 629.78, 868.62 and 419.85

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Solution

The fourth proportional to 629.78, 868.62 and 419.85 is: 579.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    629.78 : 868.62 = 419.85 : x
  2. Step 2: Convert to fraction form
    629.78/868.62 = 419.85/x
  3. Step 3: Cross multiply
    629.78x = 868.62 × 419.85
  4. Step 4: Simplify right side
    629.78x = 364,691.68
  5. Step 5: Solve for x
    x = 364,691.68/629.78
  6. Step 6: Final answer
    x = 579.08

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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.