Finding the Fourth Proportional to 1,355.67, 1,870.90 and 858.13

Step by Step Solution

1. Step 1: Write the proportion equation
   1,355.67 : 1,870.90 = 858.13 : x
2. Step 2: Convert to fraction form
   1,355.67/1,870.90 = 858.13/x
3. Step 3: Cross multiply
   1,355.67x = 1,870.90 × 858.13
4. Step 4: Simplify right side
   1,355.67x = 1,605,468.59
5. Step 5: Solve for x
   x = 1,605,468.59/1,355.67
6. Step 6: Final answer
   x = 1,184.26