Finding the Fourth Proportional to 12,784.64, 19,168.86 and 5,394.20

Step by Step Solution

1. Step 1: Write the proportion equation
   12,784.64 : 19,168.86 = 5,394.20 : x
2. Step 2: Convert to fraction form
   12,784.64/19,168.86 = 5,394.20/x
3. Step 3: Cross multiply
   12,784.64x = 19,168.86 × 5,394.20
4. Step 4: Simplify right side
   12,784.64x = 103,400,664.61
5. Step 5: Solve for x
   x = 103,400,664.61/12,784.64
6. Step 6: Final answer
   x = 8,087.88