Finding the Fourth Proportional to 2,070.24, 3,105.72 and 771.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,070.24 : 3,105.72 = 771.78 : x
2. Step 2: Convert to fraction form
   2,070.24/3,105.72 = 771.78/x
3. Step 3: Cross multiply
   2,070.24x = 3,105.72 × 771.78
4. Step 4: Simplify right side
   2,070.24x = 2,396,932.58
5. Step 5: Solve for x
   x = 2,396,932.58/2,070.24
6. Step 6: Final answer
   x = 1,157.80