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Finding the Fourth Proportional to 311.67, 429.90 and 206.71

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Solution

The fourth proportional to 311.67, 429.90 and 206.71 is: 285.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.67 : 429.90 = 206.71 : x
  2. Step 2: Convert to fraction form
    311.67/429.90 = 206.71/x
  3. Step 3: Cross multiply
    311.67x = 429.90 × 206.71
  4. Step 4: Simplify right side
    311.67x = 88,862.48
  5. Step 5: Solve for x
    x = 88,862.48/311.67
  6. Step 6: Final answer
    x = 285.12

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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.