Finding the Fourth Proportional to 2,620.98, 3,931.56 and 772.08

Step by Step Solution

1. Step 1: Write the proportion equation
   2,620.98 : 3,931.56 = 772.08 : x
2. Step 2: Convert to fraction form
   2,620.98/3,931.56 = 772.08/x
3. Step 3: Cross multiply
   2,620.98x = 3,931.56 × 772.08
4. Step 4: Simplify right side
   2,620.98x = 3,035,478.84
5. Step 5: Solve for x
   x = 3,035,478.84/2,620.98
6. Step 6: Final answer
   x = 1,158.15