Finding the Third Proportional to 31,989.75 and 68,839.50

Step by Step Solution

1. Step 1: Write the proportion equation
   31,989.75 : 68,839.50 = 68,839.50 : x
2. Step 2: Convert to fraction form
   31,989.75/68,839.50 = 68,839.50/x
3. Step 3: Cross multiply
   31,989.75x = 68,839.50 × 68,839.50
4. Step 4: Simplify right side
   31,989.75x = 4,738,876,760.25
5. Step 5: Solve for x
   x = 4,738,876,760.25/31,989.75
6. Step 6: Final answer
   x = 148,137.35