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Finding the Fourth Proportional to 391.55, 540.09 and 251.61

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Solution

The fourth proportional to 391.55, 540.09 and 251.61 is: 347.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.55 : 540.09 = 251.61 : x
  2. Step 2: Convert to fraction form
    391.55/540.09 = 251.61/x
  3. Step 3: Cross multiply
    391.55x = 540.09 × 251.61
  4. Step 4: Simplify right side
    391.55x = 135,892.04
  5. Step 5: Solve for x
    x = 135,892.04/391.55
  6. Step 6: Final answer
    x = 347.07

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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.