Finding the Fourth Proportional to 1,123.76, 1,685.69 and 393.34

Step by Step Solution

1. Step 1: Write the proportion equation
   1,123.76 : 1,685.69 = 393.34 : x
2. Step 2: Convert to fraction form
   1,123.76/1,685.69 = 393.34/x
3. Step 3: Cross multiply
   1,123.76x = 1,685.69 × 393.34
4. Step 4: Simplify right side
   1,123.76x = 663,049.30
5. Step 5: Solve for x
   x = 663,049.30/1,123.76
6. Step 6: Final answer
   x = 590.03