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Finding the Fourth Proportional to 439.78, 659.09 and 208.17

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Solution

The fourth proportional to 439.78, 659.09 and 208.17 is: 311.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    439.78 : 659.09 = 208.17 : x
  2. Step 2: Convert to fraction form
    439.78/659.09 = 208.17/x
  3. Step 3: Cross multiply
    439.78x = 659.09 × 208.17
  4. Step 4: Simplify right side
    439.78x = 137,202.11
  5. Step 5: Solve for x
    x = 137,202.11/439.78
  6. Step 6: Final answer
    x = 311.98

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.