Finding the Fourth Proportional to 2,015.80, 3,025.32 and 783.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,015.80 : 3,025.32 = 783.78 : x
2. Step 2: Convert to fraction form
   2,015.80/3,025.32 = 783.78/x
3. Step 3: Cross multiply
   2,015.80x = 3,025.32 × 783.78
4. Step 4: Simplify right side
   2,015.80x = 2,371,185.31
5. Step 5: Solve for x
   x = 2,371,185.31/2,015.80
6. Step 6: Final answer
   x = 1,176.30