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Finding the Fourth Proportional to 206.86, 285.53 and 129.30

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Solution

The fourth proportional to 206.86, 285.53 and 129.30 is: 178.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    206.86 : 285.53 = 129.30 : x
  2. Step 2: Convert to fraction form
    206.86/285.53 = 129.30/x
  3. Step 3: Cross multiply
    206.86x = 285.53 × 129.30
  4. Step 4: Simplify right side
    206.86x = 36,919.03
  5. Step 5: Solve for x
    x = 36,919.03/206.86
  6. Step 6: Final answer
    x = 178.47

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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.