Finding the Third Proportional to 81,229.50 and 108,688.50

Step by Step Solution

1. Step 1: Write the proportion equation
   81,229.50 : 108,688.50 = 108,688.50 : x
2. Step 2: Convert to fraction form
   81,229.50/108,688.50 = 108,688.50/x
3. Step 3: Cross multiply
   81,229.50x = 108,688.50 × 108,688.50
4. Step 4: Simplify right side
   81,229.50x = 11,813,190,032.25
5. Step 5: Solve for x
   x = 11,813,190,032.25/81,229.50
6. Step 6: Final answer
   x = 145,429.80