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Finding the Fourth Proportional to 641.92, 885.92 and 393.28

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Solution

The fourth proportional to 641.92, 885.92 and 393.28 is: 542.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    641.92 : 885.92 = 393.28 : x
  2. Step 2: Convert to fraction form
    641.92/885.92 = 393.28/x
  3. Step 3: Cross multiply
    641.92x = 885.92 × 393.28
  4. Step 4: Simplify right side
    641.92x = 348,414.62
  5. Step 5: Solve for x
    x = 348,414.62/641.92
  6. Step 6: Final answer
    x = 542.77

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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.