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Finding the Fourth Proportional to 639.18, 958.65 and 206.46

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Solution

The fourth proportional to 639.18, 958.65 and 206.46 is: 309.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.18 : 958.65 = 206.46 : x
  2. Step 2: Convert to fraction form
    639.18/958.65 = 206.46/x
  3. Step 3: Cross multiply
    639.18x = 958.65 × 206.46
  4. Step 4: Simplify right side
    639.18x = 197,922.88
  5. Step 5: Solve for x
    x = 197,922.88/639.18
  6. Step 6: Final answer
    x = 309.65

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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.