Finding the Fourth Proportional to 2,561.66, 3,843.42 and 830.30

Step by Step Solution

1. Step 1: Write the proportion equation
   2,561.66 : 3,843.42 = 830.30 : x
2. Step 2: Convert to fraction form
   2,561.66/3,843.42 = 830.30/x
3. Step 3: Cross multiply
   2,561.66x = 3,843.42 × 830.30
4. Step 4: Simplify right side
   2,561.66x = 3,191,191.63
5. Step 5: Solve for x
   x = 3,191,191.63/2,561.66
6. Step 6: Final answer
   x = 1,245.75