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Finding the Third Proportional to 311.81 and 681.56

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Solution

The third proportional to 311.81 and 681.56 is: 1,489.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.81 : 681.56 = 681.56 : x
  2. Step 2: Convert to fraction form
    311.81/681.56 = 681.56/x
  3. Step 3: Cross multiply
    311.81x = 681.56 × 681.56
  4. Step 4: Simplify right side
    311.81x = 464,527.44
  5. Step 5: Solve for x
    x = 464,527.44/311.81
  6. Step 6: Final answer
    x = 1,489.77

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Why These Related Problems?

These problems maintain the same ratio (2.19) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.