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Finding the Fourth Proportional to 639.38, 959.22 and 206.54

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Solution

The fourth proportional to 639.38, 959.22 and 206.54 is: 309.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.38 : 959.22 = 206.54 : x
  2. Step 2: Convert to fraction form
    639.38/959.22 = 206.54/x
  3. Step 3: Cross multiply
    639.38x = 959.22 × 206.54
  4. Step 4: Simplify right side
    639.38x = 198,112.50
  5. Step 5: Solve for x
    x = 198,112.50/639.38
  6. Step 6: Final answer
    x = 309.85

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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.