Finding the Fourth Proportional to 2,012.72, 3,019.12 and 858.48

Step by Step Solution

1. Step 1: Write the proportion equation
   2,012.72 : 3,019.12 = 858.48 : x
2. Step 2: Convert to fraction form
   2,012.72/3,019.12 = 858.48/x
3. Step 3: Cross multiply
   2,012.72x = 3,019.12 × 858.48
4. Step 4: Simplify right side
   2,012.72x = 2,591,854.14
5. Step 5: Solve for x
   x = 2,591,854.14/2,012.72
6. Step 6: Final answer
   x = 1,287.74