Finding the Third Proportional to 87,120.50 and 122,688

Step by Step Solution

1. Step 1: Write the proportion equation
   87,120.50 : 122,688 = 122,688 : x
2. Step 2: Convert to fraction form
   87,120.50/122,688 = 122,688/x
3. Step 3: Cross multiply
   87,120.50x = 122,688 × 122,688
4. Step 4: Simplify right side
   87,120.50x = 15,052,345,344
5. Step 5: Solve for x
   x = 15,052,345,344/87,120.50
6. Step 6: Final answer
   x = 172,776.16