Finding the Fourth Proportional to 3,985.98, 5,501.31 and 3,321.78

Step by Step Solution

1. Step 1: Write the proportion equation
   3,985.98 : 5,501.31 = 3,321.78 : x
2. Step 2: Convert to fraction form
   3,985.98/5,501.31 = 3,321.78/x
3. Step 3: Cross multiply
   3,985.98x = 5,501.31 × 3,321.78
4. Step 4: Simplify right side
   3,985.98x = 18,274,141.53
5. Step 5: Solve for x
   x = 18,274,141.53/3,985.98
6. Step 6: Final answer
   x = 4,584.60