Finding the Fourth Proportional to 9,005.28, 12,429.36 and 5,280.48

Step by Step Solution

1. Step 1: Write the proportion equation
   9,005.28 : 12,429.36 = 5,280.48 : x
2. Step 2: Convert to fraction form
   9,005.28/12,429.36 = 5,280.48/x
3. Step 3: Cross multiply
   9,005.28x = 12,429.36 × 5,280.48
4. Step 4: Simplify right side
   9,005.28x = 65,632,986.89
5. Step 5: Solve for x
   x = 65,632,986.89/9,005.28
6. Step 6: Final answer
   x = 7,288.28