Finding the Fourth Proportional to 2,922.78, 4,386.60 and 1,280.10

Step by Step Solution

1. Step 1: Write the proportion equation
   2,922.78 : 4,386.60 = 1,280.10 : x
2. Step 2: Convert to fraction form
   2,922.78/4,386.60 = 1,280.10/x
3. Step 3: Cross multiply
   2,922.78x = 4,386.60 × 1,280.10
4. Step 4: Simplify right side
   2,922.78x = 5,615,286.66
5. Step 5: Solve for x
   x = 5,615,286.66/2,922.78
6. Step 6: Final answer
   x = 1,921.21