Finding the Fourth Proportional to 3,978.98, 5,491.65 and 3,314.78

Step by Step Solution

1. Step 1: Write the proportion equation
   3,978.98 : 5,491.65 = 3,314.78 : x
2. Step 2: Convert to fraction form
   3,978.98/5,491.65 = 3,314.78/x
3. Step 3: Cross multiply
   3,978.98x = 5,491.65 × 3,314.78
4. Step 4: Simplify right side
   3,978.98x = 18,203,611.59
5. Step 5: Solve for x
   x = 18,203,611.59/3,978.98
6. Step 6: Final answer
   x = 4,574.94