Finding the Fourth Proportional to 1,185.28, 1,635.72 and 661.30

Step by Step Solution

1. Step 1: Write the proportion equation
   1,185.28 : 1,635.72 = 661.30 : x
2. Step 2: Convert to fraction form
   1,185.28/1,635.72 = 661.30/x
3. Step 3: Cross multiply
   1,185.28x = 1,635.72 × 661.30
4. Step 4: Simplify right side
   1,185.28x = 1,081,701.64
5. Step 5: Solve for x
   x = 1,081,701.64/1,185.28
6. Step 6: Final answer
   x = 912.61