Finding the Fourth Proportional to 2,860.28, 4,290.72 and 912.02

Step by Step Solution

1. Step 1: Write the proportion equation
   2,860.28 : 4,290.72 = 912.02 : x
2. Step 2: Convert to fraction form
   2,860.28/4,290.72 = 912.02/x
3. Step 3: Cross multiply
   2,860.28x = 4,290.72 × 912.02
4. Step 4: Simplify right side
   2,860.28x = 3,913,222.45
5. Step 5: Solve for x
   x = 3,913,222.45/2,860.28
6. Step 6: Final answer
   x = 1,368.13