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Finding the Fourth Proportional to 311.10, 428.87 and 222.55

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Solution

The fourth proportional to 311.10, 428.87 and 222.55 is: 306.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.10 : 428.87 = 222.55 : x
  2. Step 2: Convert to fraction form
    311.10/428.87 = 222.55/x
  3. Step 3: Cross multiply
    311.10x = 428.87 × 222.55
  4. Step 4: Simplify right side
    311.10x = 95,443.91
  5. Step 5: Solve for x
    x = 95,443.91/311.10
  6. Step 6: Final answer
    x = 306.80

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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.