Finding the Fourth Proportional to 1,153.67, 1,728.88 and 865.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,153.67 : 1,728.88 = 865.31 : x
2. Step 2: Convert to fraction form
   1,153.67/1,728.88 = 865.31/x
3. Step 3: Cross multiply
   1,153.67x = 1,728.88 × 865.31
4. Step 4: Simplify right side
   1,153.67x = 1,496,017.15
5. Step 5: Solve for x
   x = 1,496,017.15/1,153.67
6. Step 6: Final answer
   x = 1,296.75