Finding the Fourth Proportional to 5,297.77, 7,940.89 and 3,990.25

Step by Step Solution

1. Step 1: Write the proportion equation
   5,297.77 : 7,940.89 = 3,990.25 : x
2. Step 2: Convert to fraction form
   5,297.77/7,940.89 = 3,990.25/x
3. Step 3: Cross multiply
   5,297.77x = 7,940.89 × 3,990.25
4. Step 4: Simplify right side
   5,297.77x = 31,686,136.32
5. Step 5: Solve for x
   x = 31,686,136.32/5,297.77
6. Step 6: Final answer
   x = 5,981.03