Finding the Fourth Proportional to 2,158.84, 3,235.83 and 858.79

Step by Step Solution

1. Step 1: Write the proportion equation
   2,158.84 : 3,235.83 = 858.79 : x
2. Step 2: Convert to fraction form
   2,158.84/3,235.83 = 858.79/x
3. Step 3: Cross multiply
   2,158.84x = 3,235.83 × 858.79
4. Step 4: Simplify right side
   2,158.84x = 2,778,898.45
5. Step 5: Solve for x
   x = 2,778,898.45/2,158.84
6. Step 6: Final answer
   x = 1,287.22