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Finding the Fourth Proportional to 136.92, 205.38 and 85.38

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Solution

The fourth proportional to 136.92, 205.38 and 85.38 is: 128.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    136.92 : 205.38 = 85.38 : x
  2. Step 2: Convert to fraction form
    136.92/205.38 = 85.38/x
  3. Step 3: Cross multiply
    136.92x = 205.38 × 85.38
  4. Step 4: Simplify right side
    136.92x = 17,534.92
  5. Step 5: Solve for x
    x = 17,534.92/136.92
  6. Step 6: Final answer
    x = 128.07

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.