Finding the Fourth Proportional to 2,086.75, 3,128.91 and 699.32

Step by Step Solution

1. Step 1: Write the proportion equation
   2,086.75 : 3,128.91 = 699.32 : x
2. Step 2: Convert to fraction form
   2,086.75/3,128.91 = 699.32/x
3. Step 3: Cross multiply
   2,086.75x = 3,128.91 × 699.32
4. Step 4: Simplify right side
   2,086.75x = 2,188,109.34
5. Step 5: Solve for x
   x = 2,188,109.34/2,086.75
6. Step 6: Final answer
   x = 1,048.57