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Finding the Fourth Proportional to 638.87, 958.17 and 206.15

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Solution

The fourth proportional to 638.87, 958.17 and 206.15 is: 309.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.87 : 958.17 = 206.15 : x
  2. Step 2: Convert to fraction form
    638.87/958.17 = 206.15/x
  3. Step 3: Cross multiply
    638.87x = 958.17 × 206.15
  4. Step 4: Simplify right side
    638.87x = 197,526.75
  5. Step 5: Solve for x
    x = 197,526.75/638.87
  6. Step 6: Final answer
    x = 309.18

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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.