Finding the Fourth Proportional to 1,123.64, 1,685.69 and 343.59

Step by Step Solution

1. Step 1: Write the proportion equation
   1,123.64 : 1,685.69 = 343.59 : x
2. Step 2: Convert to fraction form
   1,123.64/1,685.69 = 343.59/x
3. Step 3: Cross multiply
   1,123.64x = 1,685.69 × 343.59
4. Step 4: Simplify right side
   1,123.64x = 579,184.51
5. Step 5: Solve for x
   x = 579,184.51/1,123.64
6. Step 6: Final answer
   x = 515.46