Finding the Fourth Proportional to 2,561.62, 3,842.56 and 830.38

Step by Step Solution

1. Step 1: Write the proportion equation
   2,561.62 : 3,842.56 = 830.38 : x
2. Step 2: Convert to fraction form
   2,561.62/3,842.56 = 830.38/x
3. Step 3: Cross multiply
   2,561.62x = 3,842.56 × 830.38
4. Step 4: Simplify right side
   2,561.62x = 3,190,784.97
5. Step 5: Solve for x
   x = 3,190,784.97/2,561.62
6. Step 6: Final answer
   x = 1,245.61