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Finding the Third Proportional to 109 and 208

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Solution

The third proportional to 109 and 208 is: 396.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    109 : 208 = 208 : x
  2. Step 2: Convert to fraction form
    109/208 = 208/x
  3. Step 3: Cross multiply
    109x = 208 × 208
  4. Step 4: Simplify right side
    109x = 43,264
  5. Step 5: Solve for x
    x = 43,264/109
  6. Step 6: Final answer
    x = 396.92

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Why These Related Problems?

These problems maintain the same ratio (1.91) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.