Finding the Fourth Proportional to 1,123.80, 1,683.63 and 661.83

Step by Step Solution

1. Step 1: Write the proportion equation
   1,123.80 : 1,683.63 = 661.83 : x
2. Step 2: Convert to fraction form
   1,123.80/1,683.63 = 661.83/x
3. Step 3: Cross multiply
   1,123.80x = 1,683.63 × 661.83
4. Step 4: Simplify right side
   1,123.80x = 1,114,276.84
5. Step 5: Solve for x
   x = 1,114,276.84/1,123.80
6. Step 6: Final answer
   x = 991.53