Finding the Fourth Proportional to 1,123.05, 1,683.35 and 429.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,123.05 : 1,683.35 = 429.42 : x
2. Step 2: Convert to fraction form
   1,123.05/1,683.35 = 429.42/x
3. Step 3: Cross multiply
   1,123.05x = 1,683.35 × 429.42
4. Step 4: Simplify right side
   1,123.05x = 722,862.88
5. Step 5: Solve for x
   x = 722,862.88/1,123.05
6. Step 6: Final answer
   x = 643.66