Finding the Fourth Proportional to 10,910.72, 16,355.92 and 3,980

Step by Step Solution

1. Step 1: Write the proportion equation
   10,910.72 : 16,355.92 = 3,980 : x
2. Step 2: Convert to fraction form
   10,910.72/16,355.92 = 3,980/x
3. Step 3: Cross multiply
   10,910.72x = 16,355.92 × 3,980
4. Step 4: Simplify right side
   10,910.72x = 65,096,561.60
5. Step 5: Solve for x
   x = 65,096,561.60/10,910.72
6. Step 6: Final answer
   x = 5,966.29