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Finding the Fourth Proportional to 418.28, 627.28 and 129.72

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Solution

The fourth proportional to 418.28, 627.28 and 129.72 is: 194.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    418.28 : 627.28 = 129.72 : x
  2. Step 2: Convert to fraction form
    418.28/627.28 = 129.72/x
  3. Step 3: Cross multiply
    418.28x = 627.28 × 129.72
  4. Step 4: Simplify right side
    418.28x = 81,370.76
  5. Step 5: Solve for x
    x = 81,370.76/418.28
  6. Step 6: Final answer
    x = 194.54

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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.