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Finding the Fourth Proportional to 136.40, 188.25 and 81.17

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Solution

The fourth proportional to 136.40, 188.25 and 81.17 is: 112.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    136.40 : 188.25 = 81.17 : x
  2. Step 2: Convert to fraction form
    136.40/188.25 = 81.17/x
  3. Step 3: Cross multiply
    136.40x = 188.25 × 81.17
  4. Step 4: Simplify right side
    136.40x = 15,279.31
  5. Step 5: Solve for x
    x = 15,279.31/136.40
  6. Step 6: Final answer
    x = 112.02

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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.