Finding the Fourth Proportional to 12,209.56, 18,309.96 and 5,280.28

Step by Step Solution

1. Step 1: Write the proportion equation
   12,209.56 : 18,309.96 = 5,280.28 : x
2. Step 2: Convert to fraction form
   12,209.56/18,309.96 = 5,280.28/x
3. Step 3: Cross multiply
   12,209.56x = 18,309.96 × 5,280.28
4. Step 4: Simplify right side
   12,209.56x = 96,681,715.59
5. Step 5: Solve for x
   x = 96,681,715.59/12,209.56
6. Step 6: Final answer
   x = 7,918.53