Finding the Fourth Proportional to 2,561.58, 3,838.74 and 1,020.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,561.58 : 3,838.74 = 1,020.78 : x
2. Step 2: Convert to fraction form
   2,561.58/3,838.74 = 1,020.78/x
3. Step 3: Cross multiply
   2,561.58x = 3,838.74 × 1,020.78
4. Step 4: Simplify right side
   2,561.58x = 3,918,509.02
5. Step 5: Solve for x
   x = 3,918,509.02/2,561.58
6. Step 6: Final answer
   x = 1,529.72