Finding the Fourth Proportional to 2,718.56, 4,078.53 and 770.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,718.56 : 4,078.53 = 770.78 : x
2. Step 2: Convert to fraction form
   2,718.56/4,078.53 = 770.78/x
3. Step 3: Cross multiply
   2,718.56x = 4,078.53 × 770.78
4. Step 4: Simplify right side
   2,718.56x = 3,143,645.50
5. Step 5: Solve for x
   x = 3,143,645.50/2,718.56
6. Step 6: Final answer
   x = 1,156.36