Finding the Fourth Proportional to 2,808.98, 4,213.69 and 861.25

Step by Step Solution

1. Step 1: Write the proportion equation
   2,808.98 : 4,213.69 = 861.25 : x
2. Step 2: Convert to fraction form
   2,808.98/4,213.69 = 861.25/x
3. Step 3: Cross multiply
   2,808.98x = 4,213.69 × 861.25
4. Step 4: Simplify right side
   2,808.98x = 3,629,027.83
5. Step 5: Solve for x
   x = 3,629,027.83/2,808.98
6. Step 6: Final answer
   x = 1,291.94