Finding the Fourth Proportional to 9,630.78, 13,289.85 and 5,439.30

Step by Step Solution

1. Step 1: Write the proportion equation
   9,630.78 : 13,289.85 = 5,439.30 : x
2. Step 2: Convert to fraction form
   9,630.78/13,289.85 = 5,439.30/x
3. Step 3: Cross multiply
   9,630.78x = 13,289.85 × 5,439.30
4. Step 4: Simplify right side
   9,630.78x = 72,287,481.11
5. Step 5: Solve for x
   x = 72,287,481.11/9,630.78
6. Step 6: Final answer
   x = 7,505.88