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Finding the Fourth Proportional to 398.56, 597.90 and 138.58

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Solution

The fourth proportional to 398.56, 597.90 and 138.58 is: 207.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    398.56 : 597.90 = 138.58 : x
  2. Step 2: Convert to fraction form
    398.56/597.90 = 138.58/x
  3. Step 3: Cross multiply
    398.56x = 597.90 × 138.58
  4. Step 4: Simplify right side
    398.56x = 82,853.99
  5. Step 5: Solve for x
    x = 82,853.99/398.56
  6. Step 6: Final answer
    x = 207.89

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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.