Finding the Fourth Proportional to 1,185.15, 1,635.54 and 687.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,185.15 : 1,635.54 = 687.72 : x
2. Step 2: Convert to fraction form
   1,185.15/1,635.54 = 687.72/x
3. Step 3: Cross multiply
   1,185.15x = 1,635.54 × 687.72
4. Step 4: Simplify right side
   1,185.15x = 1,124,793.57
5. Step 5: Solve for x
   x = 1,124,793.57/1,185.15
6. Step 6: Final answer
   x = 949.07