Finding the Fourth Proportional to 8,985.78, 12,399.48 and 5,448.78

Step by Step Solution

1. Step 1: Write the proportion equation
   8,985.78 : 12,399.48 = 5,448.78 : x
2. Step 2: Convert to fraction form
   8,985.78/12,399.48 = 5,448.78/x
3. Step 3: Cross multiply
   8,985.78x = 12,399.48 × 5,448.78
4. Step 4: Simplify right side
   8,985.78x = 67,562,038.63
5. Step 5: Solve for x
   x = 67,562,038.63/8,985.78
6. Step 6: Final answer
   x = 7,518.77