Finding the Fourth Proportional to 9,578.68, 13,218.78 and 5,388.28

Step by Step Solution

1. Step 1: Write the proportion equation
   9,578.68 : 13,218.78 = 5,388.28 : x
2. Step 2: Convert to fraction form
   9,578.68/13,218.78 = 5,388.28/x
3. Step 3: Cross multiply
   9,578.68x = 13,218.78 × 5,388.28
4. Step 4: Simplify right side
   9,578.68x = 71,226,487.90
5. Step 5: Solve for x
   x = 71,226,487.90/9,578.68
6. Step 6: Final answer
   x = 7,435.94