Finding the Fourth Proportional to 139,389.96, 209,010.81 and 55,146.72

Step by Step Solution

1. Step 1: Write the proportion equation
   139,389.96 : 209,010.81 = 55,146.72 : x
2. Step 2: Convert to fraction form
   139,389.96/209,010.81 = 55,146.72/x
3. Step 3: Cross multiply
   139,389.96x = 209,010.81 × 55,146.72
4. Step 4: Simplify right side
   139,389.96x = 11,526,260,616.04
5. Step 5: Solve for x
   x = 11,526,260,616.04/139,389.96
6. Step 6: Final answer
   x = 82,690.75