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Finding the Fourth Proportional to 318.78, 439.90 and 178.90

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Solution

The fourth proportional to 318.78, 439.90 and 178.90 is: 246.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    318.78 : 439.90 = 178.90 : x
  2. Step 2: Convert to fraction form
    318.78/439.90 = 178.90/x
  3. Step 3: Cross multiply
    318.78x = 439.90 × 178.90
  4. Step 4: Simplify right side
    318.78x = 78,697.66
  5. Step 5: Solve for x
    x = 78,697.66/318.78
  6. Step 6: Final answer
    x = 246.88

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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.