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Finding the Fourth Proportional to 391.61, 539.92 and 279.53

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Solution

The fourth proportional to 391.61, 539.92 and 279.53 is: 385.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.61 : 539.92 = 279.53 : x
  2. Step 2: Convert to fraction form
    391.61/539.92 = 279.53/x
  3. Step 3: Cross multiply
    391.61x = 539.92 × 279.53
  4. Step 4: Simplify right side
    391.61x = 150,920.42
  5. Step 5: Solve for x
    x = 150,920.42/391.61
  6. Step 6: Final answer
    x = 385.38

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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.