Finding the Fourth Proportional to 1,185.58, 1,636.10 and 661.61

Step by Step Solution

1. Step 1: Write the proportion equation
   1,185.58 : 1,636.10 = 661.61 : x
2. Step 2: Convert to fraction form
   1,185.58/1,636.10 = 661.61/x
3. Step 3: Cross multiply
   1,185.58x = 1,636.10 × 661.61
4. Step 4: Simplify right side
   1,185.58x = 1,082,460.12
5. Step 5: Solve for x
   x = 1,082,460.12/1,185.58
6. Step 6: Final answer
   x = 913.02