Finding the Fourth Proportional to 10,139.28, 13,991.52 and 5,662.80

Step by Step Solution

1. Step 1: Write the proportion equation
   10,139.28 : 13,991.52 = 5,662.80 : x
2. Step 2: Convert to fraction form
   10,139.28/13,991.52 = 5,662.80/x
3. Step 3: Cross multiply
   10,139.28x = 13,991.52 × 5,662.80
4. Step 4: Simplify right side
   10,139.28x = 79,231,179.46
5. Step 5: Solve for x
   x = 79,231,179.46/10,139.28
6. Step 6: Final answer
   x = 7,814.28