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Finding the Fourth Proportional to 311.11, 428.70 and 256.24

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Solution

The fourth proportional to 311.11, 428.70 and 256.24 is: 353.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.11 : 428.70 = 256.24 : x
  2. Step 2: Convert to fraction form
    311.11/428.70 = 256.24/x
  3. Step 3: Cross multiply
    311.11x = 428.70 × 256.24
  4. Step 4: Simplify right side
    311.11x = 109,850.09
  5. Step 5: Solve for x
    x = 109,850.09/311.11
  6. Step 6: Final answer
    x = 353.09

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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.