Finding the Fourth Proportional to 1,185.58, 1,636.05 and 688.18

Step by Step Solution

1. Step 1: Write the proportion equation
   1,185.58 : 1,636.05 = 688.18 : x
2. Step 2: Convert to fraction form
   1,185.58/1,636.05 = 688.18/x
3. Step 3: Cross multiply
   1,185.58x = 1,636.05 × 688.18
4. Step 4: Simplify right side
   1,185.58x = 1,125,896.89
5. Step 5: Solve for x
   x = 1,125,896.89/1,185.58
6. Step 6: Final answer
   x = 949.66