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Finding the Fourth Proportional to 212.05, 318.11 and 103.85

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Solution

The fourth proportional to 212.05, 318.11 and 103.85 is: 155.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    212.05 : 318.11 = 103.85 : x
  2. Step 2: Convert to fraction form
    212.05/318.11 = 103.85/x
  3. Step 3: Cross multiply
    212.05x = 318.11 × 103.85
  4. Step 4: Simplify right side
    212.05x = 33,033.61
  5. Step 5: Solve for x
    x = 33,033.61/212.05
  6. Step 6: Final answer
    x = 155.78

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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.