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Finding the Third Proportional to 7,800 and 12,399

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Solution

The third proportional to 7,800 and 12,399 is: 19,709.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    7,800 : 12,399 = 12,399 : x
  2. Step 2: Convert to fraction form
    7,800/12,399 = 12,399/x
  3. Step 3: Cross multiply
    7,800x = 12,399 × 12,399
  4. Step 4: Simplify right side
    7,800x = 153,735,201
  5. Step 5: Solve for x
    x = 153,735,201/7,800
  6. Step 6: Final answer
    x = 19,709.64

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Why These Related Problems?

These problems maintain the same ratio (1.59) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.