Finding the Fourth Proportional to 3,923.80, 5,399.34 and 3,621.88

Step by Step Solution

1. Step 1: Write the proportion equation
   3,923.80 : 5,399.34 = 3,621.88 : x
2. Step 2: Convert to fraction form
   3,923.80/5,399.34 = 3,621.88/x
3. Step 3: Cross multiply
   3,923.80x = 5,399.34 × 3,621.88
4. Step 4: Simplify right side
   3,923.80x = 19,555,761.56
5. Step 5: Solve for x
   x = 19,555,761.56/3,923.80
6. Step 6: Final answer
   x = 4,983.88