Finding the Fourth Proportional to 2,776.58, 4,165.55 and 828.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,776.58 : 4,165.55 = 828.78 : x
2. Step 2: Convert to fraction form
   2,776.58/4,165.55 = 828.78/x
3. Step 3: Cross multiply
   2,776.58x = 4,165.55 × 828.78
4. Step 4: Simplify right side
   2,776.58x = 3,452,333.63
5. Step 5: Solve for x
   x = 3,452,333.63/2,776.58
6. Step 6: Final answer
   x = 1,243.38