Finding the Fourth Proportional to 1,355.72, 1,871.01 and 858.51

Step by Step Solution

1. Step 1: Write the proportion equation
   1,355.72 : 1,871.01 = 858.51 : x
2. Step 2: Convert to fraction form
   1,355.72/1,871.01 = 858.51/x
3. Step 3: Cross multiply
   1,355.72x = 1,871.01 × 858.51
4. Step 4: Simplify right side
   1,355.72x = 1,606,280.80
5. Step 5: Solve for x
   x = 1,606,280.80/1,355.72
6. Step 6: Final answer
   x = 1,184.82