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Finding the Fourth Proportional to 311.15, 429.31 and 206.39

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Solution

The fourth proportional to 311.15, 429.31 and 206.39 is: 284.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.15 : 429.31 = 206.39 : x
  2. Step 2: Convert to fraction form
    311.15/429.31 = 206.39/x
  3. Step 3: Cross multiply
    311.15x = 429.31 × 206.39
  4. Step 4: Simplify right side
    311.15x = 88,605.29
  5. Step 5: Solve for x
    x = 88,605.29/311.15
  6. Step 6: Final answer
    x = 284.77

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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.