Finding the Fourth Proportional to 2,615.38, 3,922.78 and 766.51

Step by Step Solution

1. Step 1: Write the proportion equation
   2,615.38 : 3,922.78 = 766.51 : x
2. Step 2: Convert to fraction form
   2,615.38/3,922.78 = 766.51/x
3. Step 3: Cross multiply
   2,615.38x = 3,922.78 × 766.51
4. Step 4: Simplify right side
   2,615.38x = 3,006,836.46
5. Step 5: Solve for x
   x = 3,006,836.46/2,615.38
6. Step 6: Final answer
   x = 1,149.68