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Finding the Fourth Proportional to 103.40, 155.02 and 81.96

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Solution

The fourth proportional to 103.40, 155.02 and 81.96 is: 122.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    103.40 : 155.02 = 81.96 : x
  2. Step 2: Convert to fraction form
    103.40/155.02 = 81.96/x
  3. Step 3: Cross multiply
    103.40x = 155.02 × 81.96
  4. Step 4: Simplify right side
    103.40x = 12,705.44
  5. Step 5: Solve for x
    x = 12,705.44/103.40
  6. Step 6: Final answer
    x = 122.88

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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.