Finding the Fourth Proportional to 9,403.88, 12,978.68 and 5,424.16

Step by Step Solution

1. Step 1: Write the proportion equation
   9,403.88 : 12,978.68 = 5,424.16 : x
2. Step 2: Convert to fraction form
   9,403.88/12,978.68 = 5,424.16/x
3. Step 3: Cross multiply
   9,403.88x = 12,978.68 × 5,424.16
4. Step 4: Simplify right side
   9,403.88x = 70,398,436.91
5. Step 5: Solve for x
   x = 70,398,436.91/9,403.88
6. Step 6: Final answer
   x = 7,486.11