Finding the Fourth Proportional to 12,090.60, 18,128.61 and 5,522.31

Step by Step Solution

1. Step 1: Write the proportion equation
   12,090.60 : 18,128.61 = 5,522.31 : x
2. Step 2: Convert to fraction form
   12,090.60/18,128.61 = 5,522.31/x
3. Step 3: Cross multiply
   12,090.60x = 18,128.61 × 5,522.31
4. Step 4: Simplify right side
   12,090.60x = 100,111,804.29
5. Step 5: Solve for x
   x = 100,111,804.29/12,090.60
6. Step 6: Final answer
   x = 8,280.14