Finding the Fourth Proportional to 5,405.56, 8,111.99 and 2,118.25

Step by Step Solution

1. Step 1: Write the proportion equation
   5,405.56 : 8,111.99 = 2,118.25 : x
2. Step 2: Convert to fraction form
   5,405.56/8,111.99 = 2,118.25/x
3. Step 3: Cross multiply
   5,405.56x = 8,111.99 × 2,118.25
4. Step 4: Simplify right side
   5,405.56x = 17,183,222.82
5. Step 5: Solve for x
   x = 17,183,222.82/5,405.56
6. Step 6: Final answer
   x = 3,178.81