Finding the Fourth Proportional to 1,355.22, 1,868.34 and 857.61

Step by Step Solution

1. Step 1: Write the proportion equation
   1,355.22 : 1,868.34 = 857.61 : x
2. Step 2: Convert to fraction form
   1,355.22/1,868.34 = 857.61/x
3. Step 3: Cross multiply
   1,355.22x = 1,868.34 × 857.61
4. Step 4: Simplify right side
   1,355.22x = 1,602,297.73
5. Step 5: Solve for x
   x = 1,602,297.73/1,355.22
6. Step 6: Final answer
   x = 1,182.32