Finding the Fourth Proportional to 2,561.61, 3,842.75 and 918.34

Step by Step Solution

1. Step 1: Write the proportion equation
   2,561.61 : 3,842.75 = 918.34 : x
2. Step 2: Convert to fraction form
   2,561.61/3,842.75 = 918.34/x
3. Step 3: Cross multiply
   2,561.61x = 3,842.75 × 918.34
4. Step 4: Simplify right side
   2,561.61x = 3,528,951.04
5. Step 5: Solve for x
   x = 3,528,951.04/2,561.61
6. Step 6: Final answer
   x = 1,377.63