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Finding the Fourth Proportional to 639.37, 958.90 and 206.55

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Solution

The fourth proportional to 639.37, 958.90 and 206.55 is: 309.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.37 : 958.90 = 206.55 : x
  2. Step 2: Convert to fraction form
    639.37/958.90 = 206.55/x
  3. Step 3: Cross multiply
    639.37x = 958.90 × 206.55
  4. Step 4: Simplify right side
    639.37x = 198,059.76
  5. Step 5: Solve for x
    x = 198,059.76/639.37
  6. Step 6: Final answer
    x = 309.77

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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.