Finding the Fourth Proportional to 2,600.91, 3,902.78 and 1,040.65

Step by Step Solution

1. Step 1: Write the proportion equation
   2,600.91 : 3,902.78 = 1,040.65 : x
2. Step 2: Convert to fraction form
   2,600.91/3,902.78 = 1,040.65/x
3. Step 3: Cross multiply
   2,600.91x = 3,902.78 × 1,040.65
4. Step 4: Simplify right side
   2,600.91x = 4,061,420.85
5. Step 5: Solve for x
   x = 4,061,420.85/2,600.91
6. Step 6: Final answer
   x = 1,561.54