Finding the Fourth Proportional to 1,381.39, 1,906.49 and 857.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,381.39 : 1,906.49 = 857.50 : x
2. Step 2: Convert to fraction form
   1,381.39/1,906.49 = 857.50/x
3. Step 3: Cross multiply
   1,381.39x = 1,906.49 × 857.50
4. Step 4: Simplify right side
   1,381.39x = 1,634,815.18
5. Step 5: Solve for x
   x = 1,634,815.18/1,381.39
6. Step 6: Final answer
   x = 1,183.46