Finding the Fourth Proportional to 1,143.83, 1,578.47 and 646.47

Step by Step Solution

1. Step 1: Write the proportion equation
   1,143.83 : 1,578.47 = 646.47 : x
2. Step 2: Convert to fraction form
   1,143.83/1,578.47 = 646.47/x
3. Step 3: Cross multiply
   1,143.83x = 1,578.47 × 646.47
4. Step 4: Simplify right side
   1,143.83x = 1,020,430.27
5. Step 5: Solve for x
   x = 1,020,430.27/1,143.83
6. Step 6: Final answer
   x = 892.12