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Finding the Fourth Proportional to 129.09, 178.09 and 73.81

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Solution

The fourth proportional to 129.09, 178.09 and 73.81 is: 101.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    129.09 : 178.09 = 73.81 : x
  2. Step 2: Convert to fraction form
    129.09/178.09 = 73.81/x
  3. Step 3: Cross multiply
    129.09x = 178.09 × 73.81
  4. Step 4: Simplify right side
    129.09x = 13,144.82
  5. Step 5: Solve for x
    x = 13,144.82/129.09
  6. Step 6: Final answer
    x = 101.83

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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.