Finding the Fourth Proportional to 2,620.57, 3,930.10 and 771.34

Step by Step Solution

1. Step 1: Write the proportion equation
   2,620.57 : 3,930.10 = 771.34 : x
2. Step 2: Convert to fraction form
   2,620.57/3,930.10 = 771.34/x
3. Step 3: Cross multiply
   2,620.57x = 3,930.10 × 771.34
4. Step 4: Simplify right side
   2,620.57x = 3,031,443.33
5. Step 5: Solve for x
   x = 3,031,443.33/2,620.57
6. Step 6: Final answer
   x = 1,156.79