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Finding the Fourth Proportional to 311.72, 429.98 and 206.96

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Solution

The fourth proportional to 311.72, 429.98 and 206.96 is: 285.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.72 : 429.98 = 206.96 : x
  2. Step 2: Convert to fraction form
    311.72/429.98 = 206.96/x
  3. Step 3: Cross multiply
    311.72x = 429.98 × 206.96
  4. Step 4: Simplify right side
    311.72x = 88,985.48
  5. Step 5: Solve for x
    x = 88,985.48/311.72
  6. Step 6: Final answer
    x = 285.47

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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.