Finding the Fourth Proportional to 143,731.69, 198,243.47 and 105,478.31

Step by Step Solution

1. Step 1: Write the proportion equation
   143,731.69 : 198,243.47 = 105,478.31 : x
2. Step 2: Convert to fraction form
   143,731.69/198,243.47 = 105,478.31/x
3. Step 3: Cross multiply
   143,731.69x = 198,243.47 × 105,478.31
4. Step 4: Simplify right side
   143,731.69x = 20,910,386,943.44
5. Step 5: Solve for x
   x = 20,910,386,943.44/143,731.69
6. Step 6: Final answer
   x = 145,482.09