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Finding the Fourth Proportional to 311.98, 430.20 and 213.58

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Solution

The fourth proportional to 311.98, 430.20 and 213.58 is: 294.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.98 : 430.20 = 213.58 : x
  2. Step 2: Convert to fraction form
    311.98/430.20 = 213.58/x
  3. Step 3: Cross multiply
    311.98x = 430.20 × 213.58
  4. Step 4: Simplify right side
    311.98x = 91,882.12
  5. Step 5: Solve for x
    x = 91,882.12/311.98
  6. Step 6: Final answer
    x = 294.51

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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.