Finding the Fourth Proportional to 1,103.86, 1,523.30 and 661.60

Step by Step Solution

1. Step 1: Write the proportion equation
   1,103.86 : 1,523.30 = 661.60 : x
2. Step 2: Convert to fraction form
   1,103.86/1,523.30 = 661.60/x
3. Step 3: Cross multiply
   1,103.86x = 1,523.30 × 661.60
4. Step 4: Simplify right side
   1,103.86x = 1,007,815.28
5. Step 5: Solve for x
   x = 1,007,815.28/1,103.86
6. Step 6: Final answer
   x = 912.99