Finding the Third Proportional to 12,678 and 30,830

Step by Step Solution

1. Step 1: Write the proportion equation
   12,678 : 30,830 = 30,830 : x
2. Step 2: Convert to fraction form
   12,678/30,830 = 30,830/x
3. Step 3: Cross multiply
   12,678x = 30,830 × 30,830
4. Step 4: Simplify right side
   12,678x = 950,488,900
5. Step 5: Solve for x
   x = 950,488,900/12,678
6. Step 6: Final answer
   x = 74,971.52