Finding the Fourth Proportional to 139,939.47, 209,942.01 and 55,704.78

Step by Step Solution

1. Step 1: Write the proportion equation
   139,939.47 : 209,942.01 = 55,704.78 : x
2. Step 2: Convert to fraction form
   139,939.47/209,942.01 = 55,704.78/x
3. Step 3: Cross multiply
   139,939.47x = 209,942.01 × 55,704.78
4. Step 4: Simplify right side
   139,939.47x = 11,694,773,479.81
5. Step 5: Solve for x
   x = 11,694,773,479.81/139,939.47
6. Step 6: Final answer
   x = 83,570.23