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Finding the Fourth Proportional to 129.05, 193.31 and 77.66

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Solution

The fourth proportional to 129.05, 193.31 and 77.66 is: 116.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    129.05 : 193.31 = 77.66 : x
  2. Step 2: Convert to fraction form
    129.05/193.31 = 77.66/x
  3. Step 3: Cross multiply
    129.05x = 193.31 × 77.66
  4. Step 4: Simplify right side
    129.05x = 15,012.21
  5. Step 5: Solve for x
    x = 15,012.21/129.05
  6. Step 6: Final answer
    x = 116.33

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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.