Finding the Fourth Proportional to 2,012.16, 3,018.72 and 858.24

Step by Step Solution

1. Step 1: Write the proportion equation
   2,012.16 : 3,018.72 = 858.24 : x
2. Step 2: Convert to fraction form
   2,012.16/3,018.72 = 858.24/x
3. Step 3: Cross multiply
   2,012.16x = 3,018.72 × 858.24
4. Step 4: Simplify right side
   2,012.16x = 2,590,786.25
5. Step 5: Solve for x
   x = 2,590,786.25/2,012.16
6. Step 6: Final answer
   x = 1,287.56