Finding the Fourth Proportional to 1,123.36, 1,683.89 and 429.87

Step by Step Solution

1. Step 1: Write the proportion equation
   1,123.36 : 1,683.89 = 429.87 : x
2. Step 2: Convert to fraction form
   1,123.36/1,683.89 = 429.87/x
3. Step 3: Cross multiply
   1,123.36x = 1,683.89 × 429.87
4. Step 4: Simplify right side
   1,123.36x = 723,843.23
5. Step 5: Solve for x
   x = 723,843.23/1,123.36
6. Step 6: Final answer
   x = 644.36