Finding the Fourth Proportional to 12,990.54, 19,486.20 and 4,105.98

Step by Step Solution

1. Step 1: Write the proportion equation
   12,990.54 : 19,486.20 = 4,105.98 : x
2. Step 2: Convert to fraction form
   12,990.54/19,486.20 = 4,105.98/x
3. Step 3: Cross multiply
   12,990.54x = 19,486.20 × 4,105.98
4. Step 4: Simplify right side
   12,990.54x = 80,009,947.48
5. Step 5: Solve for x
   x = 80,009,947.48/12,990.54
6. Step 6: Final answer
   x = 6,159.09