Finding the Fourth Proportional to 139,400.13, 192,365.91 and 78,969.54

Step by Step Solution

1. Step 1: Write the proportion equation
   139,400.13 : 192,365.91 = 78,969.54 : x
2. Step 2: Convert to fraction form
   139,400.13/192,365.91 = 78,969.54/x
3. Step 3: Cross multiply
   139,400.13x = 192,365.91 × 78,969.54
4. Step 4: Simplify right side
   139,400.13x = 15,191,047,424.38
5. Step 5: Solve for x
   x = 15,191,047,424.38/139,400.13
6. Step 6: Final answer
   x = 108,974.41