Finding the Fourth Proportional to 12,945.89, 17,865.16 and 7,280.64

Step by Step Solution

1. Step 1: Write the proportion equation
   12,945.89 : 17,865.16 = 7,280.64 : x
2. Step 2: Convert to fraction form
   12,945.89/17,865.16 = 7,280.64/x
3. Step 3: Cross multiply
   12,945.89x = 17,865.16 × 7,280.64
4. Step 4: Simplify right side
   12,945.89x = 130,069,706.69
5. Step 5: Solve for x
   x = 130,069,706.69/12,945.89
6. Step 6: Final answer
   x = 10,047.18