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Finding the Fourth Proportional to 639.92, 959.85 and 207.05

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Solution

The fourth proportional to 639.92, 959.85 and 207.05 is: 310.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.92 : 959.85 = 207.05 : x
  2. Step 2: Convert to fraction form
    639.92/959.85 = 207.05/x
  3. Step 3: Cross multiply
    639.92x = 959.85 × 207.05
  4. Step 4: Simplify right side
    639.92x = 198,732.14
  5. Step 5: Solve for x
    x = 198,732.14/639.92
  6. Step 6: Final answer
    x = 310.56

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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.