Finding the Fourth Proportional to 1,123.89, 1,684.67 and 393.09

Step by Step Solution

1. Step 1: Write the proportion equation
   1,123.89 : 1,684.67 = 393.09 : x
2. Step 2: Convert to fraction form
   1,123.89/1,684.67 = 393.09/x
3. Step 3: Cross multiply
   1,123.89x = 1,684.67 × 393.09
4. Step 4: Simplify right side
   1,123.89x = 662,224.96
5. Step 5: Solve for x
   x = 662,224.96/1,123.89
6. Step 6: Final answer
   x = 589.23