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Finding the Fourth Proportional to 311.03, 428.78 and 222.49

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Solution

The fourth proportional to 311.03, 428.78 and 222.49 is: 306.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.03 : 428.78 = 222.49 : x
  2. Step 2: Convert to fraction form
    311.03/428.78 = 222.49/x
  3. Step 3: Cross multiply
    311.03x = 428.78 × 222.49
  4. Step 4: Simplify right side
    311.03x = 95,399.26
  5. Step 5: Solve for x
    x = 95,399.26/311.03
  6. Step 6: Final answer
    x = 306.72

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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.