Finding the Fourth Proportional to 2,619.42, 3,928.05 and 769.86

Step by Step Solution

1. Step 1: Write the proportion equation
   2,619.42 : 3,928.05 = 769.86 : x
2. Step 2: Convert to fraction form
   2,619.42/3,928.05 = 769.86/x
3. Step 3: Cross multiply
   2,619.42x = 3,928.05 × 769.86
4. Step 4: Simplify right side
   2,619.42x = 3,024,048.57
5. Step 5: Solve for x
   x = 3,024,048.57/2,619.42
6. Step 6: Final answer
   x = 1,154.47