Finding the Fourth Proportional to 1,185.56, 1,636.20 and 661.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,185.56 : 1,636.20 = 661.72 : x
2. Step 2: Convert to fraction form
   1,185.56/1,636.20 = 661.72/x
3. Step 3: Cross multiply
   1,185.56x = 1,636.20 × 661.72
4. Step 4: Simplify right side
   1,185.56x = 1,082,706.26
5. Step 5: Solve for x
   x = 1,082,706.26/1,185.56
6. Step 6: Final answer
   x = 913.24