Finding the Fourth Proportional to 1,150.88, 1,588.39 and 685.40

Step by Step Solution

1. Step 1: Write the proportion equation
   1,150.88 : 1,588.39 = 685.40 : x
2. Step 2: Convert to fraction form
   1,150.88/1,588.39 = 685.40/x
3. Step 3: Cross multiply
   1,150.88x = 1,588.39 × 685.40
4. Step 4: Simplify right side
   1,150.88x = 1,088,672.85
5. Step 5: Solve for x
   x = 1,088,672.85/1,150.88
6. Step 6: Final answer
   x = 945.95