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Finding the Third Proportional to 307 and 639.88

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Solution

The third proportional to 307 and 639.88 is: 1,333.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    307 : 639.88 = 639.88 : x
  2. Step 2: Convert to fraction form
    307/639.88 = 639.88/x
  3. Step 3: Cross multiply
    307x = 639.88 × 639.88
  4. Step 4: Simplify right side
    307x = 409,440.02
  5. Step 5: Solve for x
    x = 409,440.02/307
  6. Step 6: Final answer
    x = 1,333.68

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Why These Related Problems?

These problems maintain the same ratio (2.08) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.