Finding the Fourth Proportional to 12,904.78, 19,369.05 and 7,984.03

Step by Step Solution

1. Step 1: Write the proportion equation
   12,904.78 : 19,369.05 = 7,984.03 : x
2. Step 2: Convert to fraction form
   12,904.78/19,369.05 = 7,984.03/x
3. Step 3: Cross multiply
   12,904.78x = 19,369.05 × 7,984.03
4. Step 4: Simplify right side
   12,904.78x = 154,643,076.27
5. Step 5: Solve for x
   x = 154,643,076.27/12,904.78
6. Step 6: Final answer
   x = 11,983.40