Finding the Fourth Proportional to 2,648.13, 3,969.60 and 1,261.09

Step by Step Solution

1. Step 1: Write the proportion equation
   2,648.13 : 3,969.60 = 1,261.09 : x
2. Step 2: Convert to fraction form
   2,648.13/3,969.60 = 1,261.09/x
3. Step 3: Cross multiply
   2,648.13x = 3,969.60 × 1,261.09
4. Step 4: Simplify right side
   2,648.13x = 5,006,032.56
5. Step 5: Solve for x
   x = 5,006,032.56/2,648.13
6. Step 6: Final answer
   x = 1,890.41