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Finding the Fourth Proportional to 311.12, 428.68 and 223.76

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Solution

The fourth proportional to 311.12, 428.68 and 223.76 is: 308.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.12 : 428.68 = 223.76 : x
  2. Step 2: Convert to fraction form
    311.12/428.68 = 223.76/x
  3. Step 3: Cross multiply
    311.12x = 428.68 × 223.76
  4. Step 4: Simplify right side
    311.12x = 95,921.44
  5. Step 5: Solve for x
    x = 95,921.44/311.12
  6. Step 6: Final answer
    x = 308.31

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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.