Finding the Fourth Proportional to 2,076.80, 3,116.82 and 778.64

Step by Step Solution

1. Step 1: Write the proportion equation
   2,076.80 : 3,116.82 = 778.64 : x
2. Step 2: Convert to fraction form
   2,076.80/3,116.82 = 778.64/x
3. Step 3: Cross multiply
   2,076.80x = 3,116.82 × 778.64
4. Step 4: Simplify right side
   2,076.80x = 2,426,880.72
5. Step 5: Solve for x
   x = 2,426,880.72/2,076.80
6. Step 6: Final answer
   x = 1,168.57