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Finding the Third Proportional to 680.50 and 1,385

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Solution

The third proportional to 680.50 and 1,385 is: 2,818.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.50 : 1,385 = 1,385 : x
  2. Step 2: Convert to fraction form
    680.50/1,385 = 1,385/x
  3. Step 3: Cross multiply
    680.50x = 1,385 × 1,385
  4. Step 4: Simplify right side
    680.50x = 1,918,225
  5. Step 5: Solve for x
    x = 1,918,225/680.50
  6. Step 6: Final answer
    x = 2,818.85

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These problems maintain the same ratio (2.04) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.