Finding the Fourth Proportional to 2,561.27, 3,842.66 and 917.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,561.27 : 3,842.66 = 917.78 : x
2. Step 2: Convert to fraction form
   2,561.27/3,842.66 = 917.78/x
3. Step 3: Cross multiply
   2,561.27x = 3,842.66 × 917.78
4. Step 4: Simplify right side
   2,561.27x = 3,526,692.69
5. Step 5: Solve for x
   x = 3,526,692.69/2,561.27
6. Step 6: Final answer
   x = 1,376.93