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Finding the Third Proportional to 321,780 and 686,280

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Solution

The third proportional to 321,780 and 686,280 is: 1,463,671.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    321,780 : 686,280 = 686,280 : x
  2. Step 2: Convert to fraction form
    321,780/686,280 = 686,280/x
  3. Step 3: Cross multiply
    321,780x = 686,280 × 686,280
  4. Step 4: Simplify right side
    321,780x = 470,980,238,400
  5. Step 5: Solve for x
    x = 470,980,238,400/321,780
  6. Step 6: Final answer
    x = 1,463,671.57

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Why These Related Problems?

These problems maintain the same ratio (2.13) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.