Finding the Fourth Proportional to 2,920.78, 4,383.15 and 1,276.38

Step by Step Solution

1. Step 1: Write the proportion equation
   2,920.78 : 4,383.15 = 1,276.38 : x
2. Step 2: Convert to fraction form
   2,920.78/4,383.15 = 1,276.38/x
3. Step 3: Cross multiply
   2,920.78x = 4,383.15 × 1,276.38
4. Step 4: Simplify right side
   2,920.78x = 5,594,560.21
5. Step 5: Solve for x
   x = 5,594,560.21/2,920.78
6. Step 6: Final answer
   x = 1,915.43