Finding the Fourth Proportional to 1,185.50, 1,636 and 661.64

Step by Step Solution

1. Step 1: Write the proportion equation
   1,185.50 : 1,636 = 661.64 : x
2. Step 2: Convert to fraction form
   1,185.50/1,636 = 661.64/x
3. Step 3: Cross multiply
   1,185.50x = 1,636 × 661.64
4. Step 4: Simplify right side
   1,185.50x = 1,082,443.04
5. Step 5: Solve for x
   x = 1,082,443.04/1,185.50
6. Step 6: Final answer
   x = 913.07