Finding the Fourth Proportional to 12,899.36, 19,342.56 and 5,978.72

Step by Step Solution

1. Step 1: Write the proportion equation
   12,899.36 : 19,342.56 = 5,978.72 : x
2. Step 2: Convert to fraction form
   12,899.36/19,342.56 = 5,978.72/x
3. Step 3: Cross multiply
   12,899.36x = 19,342.56 × 5,978.72
4. Step 4: Simplify right side
   12,899.36x = 115,643,750.32
5. Step 5: Solve for x
   x = 115,643,750.32/12,899.36
6. Step 6: Final answer
   x = 8,965.08