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Finding the Fourth Proportional to 138.56, 206.76 and 135.28

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Solution

The fourth proportional to 138.56, 206.76 and 135.28 is: 201.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.56 : 206.76 = 135.28 : x
  2. Step 2: Convert to fraction form
    138.56/206.76 = 135.28/x
  3. Step 3: Cross multiply
    138.56x = 206.76 × 135.28
  4. Step 4: Simplify right side
    138.56x = 27,970.49
  5. Step 5: Solve for x
    x = 27,970.49/138.56
  6. Step 6: Final answer
    x = 201.87

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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.