Finding the Fourth Proportional to 12,309.69, 18,462.72 and 3,990.43

Step by Step Solution

1. Step 1: Write the proportion equation
   12,309.69 : 18,462.72 = 3,990.43 : x
2. Step 2: Convert to fraction form
   12,309.69/18,462.72 = 3,990.43/x
3. Step 3: Cross multiply
   12,309.69x = 18,462.72 × 3,990.43
4. Step 4: Simplify right side
   12,309.69x = 73,674,191.77
5. Step 5: Solve for x
   x = 73,674,191.77/12,309.69
6. Step 6: Final answer
   x = 5,985.06