Finding the Fourth Proportional to 2,610.40, 3,916.83 and 1,312.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,610.40 : 3,916.83 = 1,312.78 : x
2. Step 2: Convert to fraction form
   2,610.40/3,916.83 = 1,312.78/x
3. Step 3: Cross multiply
   2,610.40x = 3,916.83 × 1,312.78
4. Step 4: Simplify right side
   2,610.40x = 5,141,936.09
5. Step 5: Solve for x
   x = 5,141,936.09/2,610.40
6. Step 6: Final answer
   x = 1,969.79