Finding the Fourth Proportional to 2,085.45, 3,127.83 and 698.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,085.45 : 3,127.83 = 698.78 : x
2. Step 2: Convert to fraction form
   2,085.45/3,127.83 = 698.78/x
3. Step 3: Cross multiply
   2,085.45x = 3,127.83 × 698.78
4. Step 4: Simplify right side
   2,085.45x = 2,185,649.41
5. Step 5: Solve for x
   x = 2,185,649.41/2,085.45
6. Step 6: Final answer
   x = 1,048.05