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Finding the Fourth Proportional to 638.90, 958.34 and 206.09

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Solution

The fourth proportional to 638.90, 958.34 and 206.09 is: 309.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.90 : 958.34 = 206.09 : x
  2. Step 2: Convert to fraction form
    638.90/958.34 = 206.09/x
  3. Step 3: Cross multiply
    638.90x = 958.34 × 206.09
  4. Step 4: Simplify right side
    638.90x = 197,504.29
  5. Step 5: Solve for x
    x = 197,504.29/638.90
  6. Step 6: Final answer
    x = 309.13

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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.