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Finding the Fourth Proportional to 398.66, 598.05 and 138.65

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Solution

The fourth proportional to 398.66, 598.05 and 138.65 is: 207.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    398.66 : 598.05 = 138.65 : x
  2. Step 2: Convert to fraction form
    398.66/598.05 = 138.65/x
  3. Step 3: Cross multiply
    398.66x = 598.05 × 138.65
  4. Step 4: Simplify right side
    398.66x = 82,916.64
  5. Step 5: Solve for x
    x = 82,916.64/398.66
  6. Step 6: Final answer
    x = 207.99

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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.