Finding the Fourth Proportional to 2,620.53, 3,930.75 and 772.89

Step by Step Solution

1. Step 1: Write the proportion equation
   2,620.53 : 3,930.75 = 772.89 : x
2. Step 2: Convert to fraction form
   2,620.53/3,930.75 = 772.89/x
3. Step 3: Cross multiply
   2,620.53x = 3,930.75 × 772.89
4. Step 4: Simplify right side
   2,620.53x = 3,038,046.91
5. Step 5: Solve for x
   x = 3,038,046.91/2,620.53
6. Step 6: Final answer
   x = 1,159.33