Finding the Third Proportional to 31,679.86 and 68,872.78

Step by Step Solution

1. Step 1: Write the proportion equation
   31,679.86 : 68,872.78 = 68,872.78 : x
2. Step 2: Convert to fraction form
   31,679.86/68,872.78 = 68,872.78/x
3. Step 3: Cross multiply
   31,679.86x = 68,872.78 × 68,872.78
4. Step 4: Simplify right side
   31,679.86x = 4,743,459,997.11
5. Step 5: Solve for x
   x = 4,743,459,997.11/31,679.86
6. Step 6: Final answer
   x = 149,731.09