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Finding the Fourth Proportional to 130.72, 196.09 and 81.92

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Solution

The fourth proportional to 130.72, 196.09 and 81.92 is: 122.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    130.72 : 196.09 = 81.92 : x
  2. Step 2: Convert to fraction form
    130.72/196.09 = 81.92/x
  3. Step 3: Cross multiply
    130.72x = 196.09 × 81.92
  4. Step 4: Simplify right side
    130.72x = 16,063.28
  5. Step 5: Solve for x
    x = 16,063.28/130.72
  6. Step 6: Final answer
    x = 122.89

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.