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Finding the Third Proportional to 311.82 and 681.30

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Solution

The third proportional to 311.82 and 681.30 is: 1,488.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.82 : 681.30 = 681.30 : x
  2. Step 2: Convert to fraction form
    311.82/681.30 = 681.30/x
  3. Step 3: Cross multiply
    311.82x = 681.30 × 681.30
  4. Step 4: Simplify right side
    311.82x = 464,172.09
  5. Step 5: Solve for x
    x = 464,172.09/311.82
  6. Step 6: Final answer
    x = 1,488.60

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Why These Related Problems?

These problems maintain the same ratio (2.18) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.