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Finding the Fourth Proportional to 311.06, 429.40 and 206.20

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Solution

The fourth proportional to 311.06, 429.40 and 206.20 is: 284.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.06 : 429.40 = 206.20 : x
  2. Step 2: Convert to fraction form
    311.06/429.40 = 206.20/x
  3. Step 3: Cross multiply
    311.06x = 429.40 × 206.20
  4. Step 4: Simplify right side
    311.06x = 88,542.28
  5. Step 5: Solve for x
    x = 88,542.28/311.06
  6. Step 6: Final answer
    x = 284.65

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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.