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Finding the Third Proportional to 10 and 20

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Solution

The third proportional to 10 and 20 is: 40

Step by Step Solution

  1. Step 1: Write the proportion equation
    10 : 20 = 20 : x
  2. Step 2: Convert to fraction form
    10/20 = 20/x
  3. Step 3: Cross multiply
    10x = 20 × 20
  4. Step 4: Simplify right side
    10x = 400
  5. Step 5: Solve for x
    x = 400/10
  6. Step 6: Final answer
    x = 40

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Why These Related Problems?

These problems maintain the same ratio (2) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.