Finding the Fourth Proportional to 1,355.89, 1,870.29 and 857.68

Step by Step Solution

1. Step 1: Write the proportion equation
   1,355.89 : 1,870.29 = 857.68 : x
2. Step 2: Convert to fraction form
   1,355.89/1,870.29 = 857.68/x
3. Step 3: Cross multiply
   1,355.89x = 1,870.29 × 857.68
4. Step 4: Simplify right side
   1,355.89x = 1,604,110.33
5. Step 5: Solve for x
   x = 1,604,110.33/1,355.89
6. Step 6: Final answer
   x = 1,183.07