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Finding the Fourth Proportional to 398.61, 597.87 and 138.56

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Solution

The fourth proportional to 398.61, 597.87 and 138.56 is: 207.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    398.61 : 597.87 = 138.56 : x
  2. Step 2: Convert to fraction form
    398.61/597.87 = 138.56/x
  3. Step 3: Cross multiply
    398.61x = 597.87 × 138.56
  4. Step 4: Simplify right side
    398.61x = 82,840.17
  5. Step 5: Solve for x
    x = 82,840.17/398.61
  6. Step 6: Final answer
    x = 207.82

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.