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Finding the Fourth Proportional to 129.64, 178.70 and 92.72

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Solution

The fourth proportional to 129.64, 178.70 and 92.72 is: 127.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    129.64 : 178.70 = 92.72 : x
  2. Step 2: Convert to fraction form
    129.64/178.70 = 92.72/x
  3. Step 3: Cross multiply
    129.64x = 178.70 × 92.72
  4. Step 4: Simplify right side
    129.64x = 16,569.06
  5. Step 5: Solve for x
    x = 16,569.06/129.64
  6. Step 6: Final answer
    x = 127.81

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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.