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Finding the Fourth Proportional to 419.73, 578.88 and 391.78

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Solution

The fourth proportional to 419.73, 578.88 and 391.78 is: 540.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    419.73 : 578.88 = 391.78 : x
  2. Step 2: Convert to fraction form
    419.73/578.88 = 391.78/x
  3. Step 3: Cross multiply
    419.73x = 578.88 × 391.78
  4. Step 4: Simplify right side
    419.73x = 226,793.61
  5. Step 5: Solve for x
    x = 226,793.61/419.73
  6. Step 6: Final answer
    x = 540.33

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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.