Finding the Fourth Proportional to 139,066.78, 208,608.99 and 53,718.35

Step by Step Solution

1. Step 1: Write the proportion equation
   139,066.78 : 208,608.99 = 53,718.35 : x
2. Step 2: Convert to fraction form
   139,066.78/208,608.99 = 53,718.35/x
3. Step 3: Cross multiply
   139,066.78x = 208,608.99 × 53,718.35
4. Step 4: Simplify right side
   139,066.78x = 11,206,130,469.37
5. Step 5: Solve for x
   x = 11,206,130,469.37/139,066.78
6. Step 6: Final answer
   x = 80,580.93