Finding the Fourth Proportional to 13,300.78, 19,951.12 and 3,940.88

Step by Step Solution

1. Step 1: Write the proportion equation
   13,300.78 : 19,951.12 = 3,940.88 : x
2. Step 2: Convert to fraction form
   13,300.78/19,951.12 = 3,940.88/x
3. Step 3: Cross multiply
   13,300.78x = 19,951.12 × 3,940.88
4. Step 4: Simplify right side
   13,300.78x = 78,624,969.79
5. Step 5: Solve for x
   x = 78,624,969.79/13,300.78
6. Step 6: Final answer
   x = 5,911.31