Finding the Fourth Proportional to 1,123.89, 1,686.05 and 343.97

Step by Step Solution

1. Step 1: Write the proportion equation
   1,123.89 : 1,686.05 = 343.97 : x
2. Step 2: Convert to fraction form
   1,123.89/1,686.05 = 343.97/x
3. Step 3: Cross multiply
   1,123.89x = 1,686.05 × 343.97
4. Step 4: Simplify right side
   1,123.89x = 579,940.47
5. Step 5: Solve for x
   x = 579,940.47/1,123.89
6. Step 6: Final answer
   x = 516.01