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Finding the Fourth Proportional to 129.57, 192.87 and 128.88

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Solution

The fourth proportional to 129.57, 192.87 and 128.88 is: 191.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    129.57 : 192.87 = 128.88 : x
  2. Step 2: Convert to fraction form
    129.57/192.87 = 128.88/x
  3. Step 3: Cross multiply
    129.57x = 192.87 × 128.88
  4. Step 4: Simplify right side
    129.57x = 24,857.09
  5. Step 5: Solve for x
    x = 24,857.09/129.57
  6. Step 6: Final answer
    x = 191.84

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.