Finding the Fourth Proportional to 9,390.49, 12,960.57 and 5,357.90

Step by Step Solution

1. Step 1: Write the proportion equation
   9,390.49 : 12,960.57 = 5,357.90 : x
2. Step 2: Convert to fraction form
   9,390.49/12,960.57 = 5,357.90/x
3. Step 3: Cross multiply
   9,390.49x = 12,960.57 × 5,357.90
4. Step 4: Simplify right side
   9,390.49x = 69,441,490.50
5. Step 5: Solve for x
   x = 69,441,490.50/9,390.49
6. Step 6: Final answer
   x = 7,394.88