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Finding the Fourth Proportional to 136.89, 189.13 and 87.88

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Solution

The fourth proportional to 136.89, 189.13 and 87.88 is: 121.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    136.89 : 189.13 = 87.88 : x
  2. Step 2: Convert to fraction form
    136.89/189.13 = 87.88/x
  3. Step 3: Cross multiply
    136.89x = 189.13 × 87.88
  4. Step 4: Simplify right side
    136.89x = 16,620.74
  5. Step 5: Solve for x
    x = 16,620.74/136.89
  6. Step 6: Final answer
    x = 121.42

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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.