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Finding the Fourth Proportional to 318.10, 439.20 and 220.09

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Solution

The fourth proportional to 318.10, 439.20 and 220.09 is: 303.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    318.10 : 439.20 = 220.09 : x
  2. Step 2: Convert to fraction form
    318.10/439.20 = 220.09/x
  3. Step 3: Cross multiply
    318.10x = 439.20 × 220.09
  4. Step 4: Simplify right side
    318.10x = 96,663.53
  5. Step 5: Solve for x
    x = 96,663.53/318.10
  6. Step 6: Final answer
    x = 303.88

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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.