Finding the Fourth Proportional to 12,728.16, 19,087.20 and 3,840.72

Step by Step Solution

1. Step 1: Write the proportion equation
   12,728.16 : 19,087.20 = 3,840.72 : x
2. Step 2: Convert to fraction form
   12,728.16/19,087.20 = 3,840.72/x
3. Step 3: Cross multiply
   12,728.16x = 19,087.20 × 3,840.72
4. Step 4: Simplify right side
   12,728.16x = 73,308,590.78
5. Step 5: Solve for x
   x = 73,308,590.78/12,728.16
6. Step 6: Final answer
   x = 5,759.56