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Finding the Fourth Proportional to 129.52, 178.60 and 120.20

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Solution

The fourth proportional to 129.52, 178.60 and 120.20 is: 165.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    129.52 : 178.60 = 120.20 : x
  2. Step 2: Convert to fraction form
    129.52/178.60 = 120.20/x
  3. Step 3: Cross multiply
    129.52x = 178.60 × 120.20
  4. Step 4: Simplify right side
    129.52x = 21,467.72
  5. Step 5: Solve for x
    x = 21,467.72/129.52
  6. Step 6: Final answer
    x = 165.75

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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.