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Finding the Fourth Proportional to 391.32, 542.52 and 385.20

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Solution

The fourth proportional to 391.32, 542.52 and 385.20 is: 534.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.32 : 542.52 = 385.20 : x
  2. Step 2: Convert to fraction form
    391.32/542.52 = 385.20/x
  3. Step 3: Cross multiply
    391.32x = 542.52 × 385.20
  4. Step 4: Simplify right side
    391.32x = 208,978.70
  5. Step 5: Solve for x
    x = 208,978.70/391.32
  6. Step 6: Final answer
    x = 534.04

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.