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Finding the Fourth Proportional to 136.92, 188.95 and 78.71

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Solution

The fourth proportional to 136.92, 188.95 and 78.71 is: 108.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    136.92 : 188.95 = 78.71 : x
  2. Step 2: Convert to fraction form
    136.92/188.95 = 78.71/x
  3. Step 3: Cross multiply
    136.92x = 188.95 × 78.71
  4. Step 4: Simplify right side
    136.92x = 14,871.31
  5. Step 5: Solve for x
    x = 14,871.31/136.92
  6. Step 6: Final answer
    x = 108.61

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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.