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Finding the Fourth Proportional to 138.20, 190.96 and 102.70

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Solution

The fourth proportional to 138.20, 190.96 and 102.70 is: 141.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.20 : 190.96 = 102.70 : x
  2. Step 2: Convert to fraction form
    138.20/190.96 = 102.70/x
  3. Step 3: Cross multiply
    138.20x = 190.96 × 102.70
  4. Step 4: Simplify right side
    138.20x = 19,611.59
  5. Step 5: Solve for x
    x = 19,611.59/138.20
  6. Step 6: Final answer
    x = 141.91

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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.