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Finding the Fourth Proportional to 129.20, 177.52 and 123.60

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Solution

The fourth proportional to 129.20, 177.52 and 123.60 is: 169.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    129.20 : 177.52 = 123.60 : x
  2. Step 2: Convert to fraction form
    129.20/177.52 = 123.60/x
  3. Step 3: Cross multiply
    129.20x = 177.52 × 123.60
  4. Step 4: Simplify right side
    129.20x = 21,941.47
  5. Step 5: Solve for x
    x = 21,941.47/129.20
  6. Step 6: Final answer
    x = 169.83

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.