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Finding the Fourth Proportional to 217.20, 325.38 and 120.72

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Solution

The fourth proportional to 217.20, 325.38 and 120.72 is: 180.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    217.20 : 325.38 = 120.72 : x
  2. Step 2: Convert to fraction form
    217.20/325.38 = 120.72/x
  3. Step 3: Cross multiply
    217.20x = 325.38 × 120.72
  4. Step 4: Simplify right side
    217.20x = 39,279.87
  5. Step 5: Solve for x
    x = 39,279.87/217.20
  6. Step 6: Final answer
    x = 180.85

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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.