Finding the Fourth Proportional to 2,707.76, 4,061.60 and 858.88

Step by Step Solution

1. Step 1: Write the proportion equation
   2,707.76 : 4,061.60 = 858.88 : x
2. Step 2: Convert to fraction form
   2,707.76/4,061.60 = 858.88/x
3. Step 3: Cross multiply
   2,707.76x = 4,061.60 × 858.88
4. Step 4: Simplify right side
   2,707.76x = 3,488,427.01
5. Step 5: Solve for x
   x = 3,488,427.01/2,707.76
6. Step 6: Final answer
   x = 1,288.31