Finding the Fourth Proportional to 2,815.89, 4,223.57 and 867.57

Step by Step Solution

1. Step 1: Write the proportion equation
   2,815.89 : 4,223.57 = 867.57 : x
2. Step 2: Convert to fraction form
   2,815.89/4,223.57 = 867.57/x
3. Step 3: Cross multiply
   2,815.89x = 4,223.57 × 867.57
4. Step 4: Simplify right side
   2,815.89x = 3,664,252.10
5. Step 5: Solve for x
   x = 3,664,252.10/2,815.89
6. Step 6: Final answer
   x = 1,301.28