Finding the Fourth Proportional to 2,085.56, 3,128.38 and 698.64

Step by Step Solution

1. Step 1: Write the proportion equation
   2,085.56 : 3,128.38 = 698.64 : x
2. Step 2: Convert to fraction form
   2,085.56/3,128.38 = 698.64/x
3. Step 3: Cross multiply
   2,085.56x = 3,128.38 × 698.64
4. Step 4: Simplify right side
   2,085.56x = 2,185,611.40
5. Step 5: Solve for x
   x = 2,185,611.40/2,085.56
6. Step 6: Final answer
   x = 1,047.97