Finding the Fourth Proportional to 3,578.61, 5,367.86 and 981.55

Step by Step Solution

1. Step 1: Write the proportion equation
   3,578.61 : 5,367.86 = 981.55 : x
2. Step 2: Convert to fraction form
   3,578.61/5,367.86 = 981.55/x
3. Step 3: Cross multiply
   3,578.61x = 5,367.86 × 981.55
4. Step 4: Simplify right side
   3,578.61x = 5,268,822.98
5. Step 5: Solve for x
   x = 5,268,822.98/3,578.61
6. Step 6: Final answer
   x = 1,472.31