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Finding the Fourth Proportional to 69.05, 103.55 and 20.96

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Solution

The fourth proportional to 69.05, 103.55 and 20.96 is: 31.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    69.05 : 103.55 = 20.96 : x
  2. Step 2: Convert to fraction form
    69.05/103.55 = 20.96/x
  3. Step 3: Cross multiply
    69.05x = 103.55 × 20.96
  4. Step 4: Simplify right side
    69.05x = 2,170.30
  5. Step 5: Solve for x
    x = 2,170.30/69.05
  6. Step 6: Final answer
    x = 31.43

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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.