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Finding the Fourth Proportional to 398.20, 597.31 and 138.51

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Solution

The fourth proportional to 398.20, 597.31 and 138.51 is: 207.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    398.20 : 597.31 = 138.51 : x
  2. Step 2: Convert to fraction form
    398.20/597.31 = 138.51/x
  3. Step 3: Cross multiply
    398.20x = 597.31 × 138.51
  4. Step 4: Simplify right side
    398.20x = 82,733.06
  5. Step 5: Solve for x
    x = 82,733.06/398.20
  6. Step 6: Final answer
    x = 207.77

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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.