Finding the Fourth Proportional to 9,382.40, 12,945.57 and 5,402.78

Step by Step Solution

1. Step 1: Write the proportion equation
   9,382.40 : 12,945.57 = 5,402.78 : x
2. Step 2: Convert to fraction form
   9,382.40/12,945.57 = 5,402.78/x
3. Step 3: Cross multiply
   9,382.40x = 12,945.57 × 5,402.78
4. Step 4: Simplify right side
   9,382.40x = 69,942,066.68
5. Step 5: Solve for x
   x = 69,942,066.68/9,382.40
6. Step 6: Final answer
   x = 7,454.60