Finding the Fourth Proportional to 1,153.25, 1,591.53 and 687.77

Step by Step Solution

1. Step 1: Write the proportion equation
   1,153.25 : 1,591.53 = 687.77 : x
2. Step 2: Convert to fraction form
   1,153.25/1,591.53 = 687.77/x
3. Step 3: Cross multiply
   1,153.25x = 1,591.53 × 687.77
4. Step 4: Simplify right side
   1,153.25x = 1,094,606.59
5. Step 5: Solve for x
   x = 1,094,606.59/1,153.25
6. Step 6: Final answer
   x = 949.15