Finding the Fourth Proportional to 2,754.88, 4,131.60 and 780.40

Step by Step Solution

1. Step 1: Write the proportion equation
   2,754.88 : 4,131.60 = 780.40 : x
2. Step 2: Convert to fraction form
   2,754.88/4,131.60 = 780.40/x
3. Step 3: Cross multiply
   2,754.88x = 4,131.60 × 780.40
4. Step 4: Simplify right side
   2,754.88x = 3,224,300.64
5. Step 5: Solve for x
   x = 3,224,300.64/2,754.88
6. Step 6: Final answer
   x = 1,170.40