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Finding the Fourth Proportional to 156.82, 215.87 and 129.15

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Solution

The fourth proportional to 156.82, 215.87 and 129.15 is: 177.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    156.82 : 215.87 = 129.15 : x
  2. Step 2: Convert to fraction form
    156.82/215.87 = 129.15/x
  3. Step 3: Cross multiply
    156.82x = 215.87 × 129.15
  4. Step 4: Simplify right side
    156.82x = 27,879.61
  5. Step 5: Solve for x
    x = 27,879.61/156.82
  6. Step 6: Final answer
    x = 177.78

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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.