Finding the Fourth Proportional to 10,920.81, 16,383.78 and 3,129.42

Step by Step Solution

1. Step 1: Write the proportion equation
   10,920.81 : 16,383.78 = 3,129.42 : x
2. Step 2: Convert to fraction form
   10,920.81/16,383.78 = 3,129.42/x
3. Step 3: Cross multiply
   10,920.81x = 16,383.78 × 3,129.42
4. Step 4: Simplify right side
   10,920.81x = 51,271,728.81
5. Step 5: Solve for x
   x = 51,271,728.81/10,920.81
6. Step 6: Final answer
   x = 4,694.87