Finding the Fourth Proportional to 2,768.58, 4,153.55 and 820.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,768.58 : 4,153.55 = 820.78 : x
2. Step 2: Convert to fraction form
   2,768.58/4,153.55 = 820.78/x
3. Step 3: Cross multiply
   2,768.58x = 4,153.55 × 820.78
4. Step 4: Simplify right side
   2,768.58x = 3,409,158.01
5. Step 5: Solve for x
   x = 3,409,158.01/2,768.58
6. Step 6: Final answer
   x = 1,231.37