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Finding the Fourth Proportional to 154.20, 212.42 and 129.62

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Solution

The fourth proportional to 154.20, 212.42 and 129.62 is: 178.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    154.20 : 212.42 = 129.62 : x
  2. Step 2: Convert to fraction form
    154.20/212.42 = 129.62/x
  3. Step 3: Cross multiply
    154.20x = 212.42 × 129.62
  4. Step 4: Simplify right side
    154.20x = 27,533.88
  5. Step 5: Solve for x
    x = 27,533.88/154.20
  6. Step 6: Final answer
    x = 178.56

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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.