Finding the Third Proportional to 51,166.69 and 81,989.72

Step by Step Solution

1. Step 1: Write the proportion equation
   51,166.69 : 81,989.72 = 81,989.72 : x
2. Step 2: Convert to fraction form
   51,166.69/81,989.72 = 81,989.72/x
3. Step 3: Cross multiply
   51,166.69x = 81,989.72 × 81,989.72
4. Step 4: Simplify right side
   51,166.69x = 6,722,313,980.70
5. Step 5: Solve for x
   x = 6,722,313,980.70/51,166.69
6. Step 6: Final answer
   x = 131,380.68