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Finding the Fourth Proportional to 418.72, 628.14 and 144.78

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Solution

The fourth proportional to 418.72, 628.14 and 144.78 is: 217.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    418.72 : 628.14 = 144.78 : x
  2. Step 2: Convert to fraction form
    418.72/628.14 = 144.78/x
  3. Step 3: Cross multiply
    418.72x = 628.14 × 144.78
  4. Step 4: Simplify right side
    418.72x = 90,942.11
  5. Step 5: Solve for x
    x = 90,942.11/418.72
  6. Step 6: Final answer
    x = 217.19

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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.