Finding the Fourth Proportional to 1,122.82, 1,683.82 and 429.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,122.82 : 1,683.82 = 429.31 : x
2. Step 2: Convert to fraction form
   1,122.82/1,683.82 = 429.31/x
3. Step 3: Cross multiply
   1,122.82x = 1,683.82 × 429.31
4. Step 4: Simplify right side
   1,122.82x = 722,880.76
5. Step 5: Solve for x
   x = 722,880.76/1,122.82
6. Step 6: Final answer
   x = 643.81