Finding the Fourth Proportional to 1,103.79, 1,523.37 and 661.60

Step by Step Solution

1. Step 1: Write the proportion equation
   1,103.79 : 1,523.37 = 661.60 : x
2. Step 2: Convert to fraction form
   1,103.79/1,523.37 = 661.60/x
3. Step 3: Cross multiply
   1,103.79x = 1,523.37 × 661.60
4. Step 4: Simplify right side
   1,103.79x = 1,007,865.98
5. Step 5: Solve for x
   x = 1,007,865.98/1,103.79
6. Step 6: Final answer
   x = 913.09