Finding the Fourth Proportional to 12,131.69, 18,222.44 and 7,977.60

Step by Step Solution

1. Step 1: Write the proportion equation
   12,131.69 : 18,222.44 = 7,977.60 : x
2. Step 2: Convert to fraction form
   12,131.69/18,222.44 = 7,977.60/x
3. Step 3: Cross multiply
   12,131.69x = 18,222.44 × 7,977.60
4. Step 4: Simplify right side
   12,131.69x = 145,371,297.46
5. Step 5: Solve for x
   x = 145,371,297.46/12,131.69
6. Step 6: Final answer
   x = 11,982.78