Finding the Fourth Proportional to 1,123.39, 1,685.31 and 343.34

Step by Step Solution

1. Step 1: Write the proportion equation
   1,123.39 : 1,685.31 = 343.34 : x
2. Step 2: Convert to fraction form
   1,123.39/1,685.31 = 343.34/x
3. Step 3: Cross multiply
   1,123.39x = 1,685.31 × 343.34
4. Step 4: Simplify right side
   1,123.39x = 578,634.34
5. Step 5: Solve for x
   x = 578,634.34/1,123.39
6. Step 6: Final answer
   x = 515.08