Finding the Fourth Proportional to 2,815.12, 4,222.72 and 867.32

Step by Step Solution

1. Step 1: Write the proportion equation
   2,815.12 : 4,222.72 = 867.32 : x
2. Step 2: Convert to fraction form
   2,815.12/4,222.72 = 867.32/x
3. Step 3: Cross multiply
   2,815.12x = 4,222.72 × 867.32
4. Step 4: Simplify right side
   2,815.12x = 3,662,428.40
5. Step 5: Solve for x
   x = 3,662,428.40/2,815.12
6. Step 6: Final answer
   x = 1,300.99