Finding the Fourth Proportional to 1,111.92, 1,534.52 and 639.83

Step by Step Solution

1. Step 1: Write the proportion equation
   1,111.92 : 1,534.52 = 639.83 : x
2. Step 2: Convert to fraction form
   1,111.92/1,534.52 = 639.83/x
3. Step 3: Cross multiply
   1,111.92x = 1,534.52 × 639.83
4. Step 4: Simplify right side
   1,111.92x = 981,821.06
5. Step 5: Solve for x
   x = 981,821.06/1,111.92
6. Step 6: Final answer
   x = 883.00