Finding the Fourth Proportional to 9,403.76, 12,978.57 and 5,424.10

Step by Step Solution

1. Step 1: Write the proportion equation
   9,403.76 : 12,978.57 = 5,424.10 : x
2. Step 2: Convert to fraction form
   9,403.76/12,978.57 = 5,424.10/x
3. Step 3: Cross multiply
   9,403.76x = 12,978.57 × 5,424.10
4. Step 4: Simplify right side
   9,403.76x = 70,397,049.43
5. Step 5: Solve for x
   x = 70,397,049.43/9,403.76
6. Step 6: Final answer
   x = 7,486.05