Finding the Fourth Proportional to 2,561.68, 3,840.72 and 1,309.16

Step by Step Solution

1. Step 1: Write the proportion equation
   2,561.68 : 3,840.72 = 1,309.16 : x
2. Step 2: Convert to fraction form
   2,561.68/3,840.72 = 1,309.16/x
3. Step 3: Cross multiply
   2,561.68x = 3,840.72 × 1,309.16
4. Step 4: Simplify right side
   2,561.68x = 5,028,117.00
5. Step 5: Solve for x
   x = 5,028,117.00/2,561.68
6. Step 6: Final answer
   x = 1,962.82