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Finding the Fourth Proportional to 391.31, 539.98 and 225.49

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Solution

The fourth proportional to 391.31, 539.98 and 225.49 is: 311.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.31 : 539.98 = 225.49 : x
  2. Step 2: Convert to fraction form
    391.31/539.98 = 225.49/x
  3. Step 3: Cross multiply
    391.31x = 539.98 × 225.49
  4. Step 4: Simplify right side
    391.31x = 121,760.09
  5. Step 5: Solve for x
    x = 121,760.09/391.31
  6. Step 6: Final answer
    x = 311.16

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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.