Finding the Fourth Proportional to 1,355.45, 1,870.25 and 857.51

Step by Step Solution

1. Step 1: Write the proportion equation
   1,355.45 : 1,870.25 = 857.51 : x
2. Step 2: Convert to fraction form
   1,355.45/1,870.25 = 857.51/x
3. Step 3: Cross multiply
   1,355.45x = 1,870.25 × 857.51
4. Step 4: Simplify right side
   1,355.45x = 1,603,744.44
5. Step 5: Solve for x
   x = 1,603,744.44/1,355.45
6. Step 6: Final answer
   x = 1,183.18