Finding the Fourth Proportional to 2,572.80, 3,858.12 and 1,111.20

Step by Step Solution

1. Step 1: Write the proportion equation
   2,572.80 : 3,858.12 = 1,111.20 : x
2. Step 2: Convert to fraction form
   2,572.80/3,858.12 = 1,111.20/x
3. Step 3: Cross multiply
   2,572.80x = 3,858.12 × 1,111.20
4. Step 4: Simplify right side
   2,572.80x = 4,287,142.94
5. Step 5: Solve for x
   x = 4,287,142.94/2,572.80
6. Step 6: Final answer
   x = 1,666.33