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Finding the Fourth Proportional to 641.85, 885.51 and 392.97

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Solution

The fourth proportional to 641.85, 885.51 and 392.97 is: 542.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    641.85 : 885.51 = 392.97 : x
  2. Step 2: Convert to fraction form
    641.85/885.51 = 392.97/x
  3. Step 3: Cross multiply
    641.85x = 885.51 × 392.97
  4. Step 4: Simplify right side
    641.85x = 347,978.86
  5. Step 5: Solve for x
    x = 347,978.86/641.85
  6. Step 6: Final answer
    x = 542.15

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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.