Finding the Fourth Proportional to 3,386.92, 5,079.78 and 921.42

Step by Step Solution

1. Step 1: Write the proportion equation
   3,386.92 : 5,079.78 = 921.42 : x
2. Step 2: Convert to fraction form
   3,386.92/5,079.78 = 921.42/x
3. Step 3: Cross multiply
   3,386.92x = 5,079.78 × 921.42
4. Step 4: Simplify right side
   3,386.92x = 4,680,610.89
5. Step 5: Solve for x
   x = 4,680,610.89/3,386.92
6. Step 6: Final answer
   x = 1,381.97