Finding the Fourth Proportional to 2,619.52, 3,928.70 and 770.76

Step by Step Solution

1. Step 1: Write the proportion equation
   2,619.52 : 3,928.70 = 770.76 : x
2. Step 2: Convert to fraction form
   2,619.52/3,928.70 = 770.76/x
3. Step 3: Cross multiply
   2,619.52x = 3,928.70 × 770.76
4. Step 4: Simplify right side
   2,619.52x = 3,028,084.81
5. Step 5: Solve for x
   x = 3,028,084.81/2,619.52
6. Step 6: Final answer
   x = 1,155.97