Finding the Fourth Proportional to 1,185.49, 1,635.81 and 688.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,185.49 : 1,635.81 = 688.15 : x
2. Step 2: Convert to fraction form
   1,185.49/1,635.81 = 688.15/x
3. Step 3: Cross multiply
   1,185.49x = 1,635.81 × 688.15
4. Step 4: Simplify right side
   1,185.49x = 1,125,682.65
5. Step 5: Solve for x
   x = 1,125,682.65/1,185.49
6. Step 6: Final answer
   x = 949.55