Finding the Fourth Proportional to 1,185.54, 1,636.20 and 661.68

Step by Step Solution

1. Step 1: Write the proportion equation
   1,185.54 : 1,636.20 = 661.68 : x
2. Step 2: Convert to fraction form
   1,185.54/1,636.20 = 661.68/x
3. Step 3: Cross multiply
   1,185.54x = 1,636.20 × 661.68
4. Step 4: Simplify right side
   1,185.54x = 1,082,640.82
5. Step 5: Solve for x
   x = 1,082,640.82/1,185.54
6. Step 6: Final answer
   x = 913.20