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Finding the Fourth Proportional to 391.48, 540.05 and 251.55

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Solution

The fourth proportional to 391.48, 540.05 and 251.55 is: 347.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.48 : 540.05 = 251.55 : x
  2. Step 2: Convert to fraction form
    391.48/540.05 = 251.55/x
  3. Step 3: Cross multiply
    391.48x = 540.05 × 251.55
  4. Step 4: Simplify right side
    391.48x = 135,849.58
  5. Step 5: Solve for x
    x = 135,849.58/391.48
  6. Step 6: Final answer
    x = 347.02

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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.