Finding the Fourth Proportional to 12,390, 18,581.36 and 3,622.83

Step by Step Solution

1. Step 1: Write the proportion equation
   12,390 : 18,581.36 = 3,622.83 : x
2. Step 2: Convert to fraction form
   12,390/18,581.36 = 3,622.83/x
3. Step 3: Cross multiply
   12,390x = 18,581.36 × 3,622.83
4. Step 4: Simplify right side
   12,390x = 67,317,090.33
5. Step 5: Solve for x
   x = 67,317,090.33/12,390
6. Step 6: Final answer
   x = 5,433.18