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Finding the Third Proportional to 309,936 and 678,840

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Solution

The third proportional to 309,936 and 678,840 is: 1,486,835.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    309,936 : 678,840 = 678,840 : x
  2. Step 2: Convert to fraction form
    309,936/678,840 = 678,840/x
  3. Step 3: Cross multiply
    309,936x = 678,840 × 678,840
  4. Step 4: Simplify right side
    309,936x = 460,823,745,600
  5. Step 5: Solve for x
    x = 460,823,745,600/309,936
  6. Step 6: Final answer
    x = 1,486,835.17

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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.