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Finding the Third Proportional to 639.84 and 1,297.69

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Solution

The third proportional to 639.84 and 1,297.69 is: 2,631.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.84 : 1,297.69 = 1,297.69 : x
  2. Step 2: Convert to fraction form
    639.84/1,297.69 = 1,297.69/x
  3. Step 3: Cross multiply
    639.84x = 1,297.69 × 1,297.69
  4. Step 4: Simplify right side
    639.84x = 1,683,992.85
  5. Step 5: Solve for x
    x = 1,683,992.85/639.84
  6. Step 6: Final answer
    x = 2,631.88

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Why These Related Problems?

These problems maintain the same ratio (2.03) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.