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Finding the Fourth Proportional to 639.54, 959.11 and 206.59

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Solution

The fourth proportional to 639.54, 959.11 and 206.59 is: 309.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.54 : 959.11 = 206.59 : x
  2. Step 2: Convert to fraction form
    639.54/959.11 = 206.59/x
  3. Step 3: Cross multiply
    639.54x = 959.11 × 206.59
  4. Step 4: Simplify right side
    639.54x = 198,142.53
  5. Step 5: Solve for x
    x = 198,142.53/639.54
  6. Step 6: Final answer
    x = 309.82

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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.