Finding the Fourth Proportional to 2,768.56, 4,152.96 and 820.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,768.56 : 4,152.96 = 820.78 : x
2. Step 2: Convert to fraction form
   2,768.56/4,152.96 = 820.78/x
3. Step 3: Cross multiply
   2,768.56x = 4,152.96 × 820.78
4. Step 4: Simplify right side
   2,768.56x = 3,408,666.51
5. Step 5: Solve for x
   x = 3,408,666.51/2,768.56
6. Step 6: Final answer
   x = 1,231.21