Finding the Fourth Proportional to 1,153.06, 1,591.23 and 687.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,153.06 : 1,591.23 = 687.31 : x
2. Step 2: Convert to fraction form
   1,153.06/1,591.23 = 687.31/x
3. Step 3: Cross multiply
   1,153.06x = 1,591.23 × 687.31
4. Step 4: Simplify right side
   1,153.06x = 1,093,670.55
5. Step 5: Solve for x
   x = 1,093,670.55/1,153.06
6. Step 6: Final answer
   x = 948.49