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Finding the Fourth Proportional to 392.89, 542.17 and 215.85

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Solution

The fourth proportional to 392.89, 542.17 and 215.85 is: 297.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    392.89 : 542.17 = 215.85 : x
  2. Step 2: Convert to fraction form
    392.89/542.17 = 215.85/x
  3. Step 3: Cross multiply
    392.89x = 542.17 × 215.85
  4. Step 4: Simplify right side
    392.89x = 117,027.39
  5. Step 5: Solve for x
    x = 117,027.39/392.89
  6. Step 6: Final answer
    x = 297.86

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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.