Finding the Fourth Proportional to 5,405.56, 8,111.91 and 2,118.91

Step by Step Solution

1. Step 1: Write the proportion equation
   5,405.56 : 8,111.91 = 2,118.91 : x
2. Step 2: Convert to fraction form
   5,405.56/8,111.91 = 2,118.91/x
3. Step 3: Cross multiply
   5,405.56x = 8,111.91 × 2,118.91
4. Step 4: Simplify right side
   5,405.56x = 17,188,407.22
5. Step 5: Solve for x
   x = 17,188,407.22/5,405.56
6. Step 6: Final answer
   x = 3,179.76