Finding the Fourth Proportional to 2,640.80, 3,959.15 and 1,180.98

Step by Step Solution

1. Step 1: Write the proportion equation
   2,640.80 : 3,959.15 = 1,180.98 : x
2. Step 2: Convert to fraction form
   2,640.80/3,959.15 = 1,180.98/x
3. Step 3: Cross multiply
   2,640.80x = 3,959.15 × 1,180.98
4. Step 4: Simplify right side
   2,640.80x = 4,675,681.03
5. Step 5: Solve for x
   x = 4,675,681.03/2,640.80
6. Step 6: Final answer
   x = 1,770.55