Finding the Fourth Proportional to 10,139.29, 13,991.40 and 5,662.78

Step by Step Solution

1. Step 1: Write the proportion equation
   10,139.29 : 13,991.40 = 5,662.78 : x
2. Step 2: Convert to fraction form
   10,139.29/13,991.40 = 5,662.78/x
3. Step 3: Cross multiply
   10,139.29x = 13,991.40 × 5,662.78
4. Step 4: Simplify right side
   10,139.29x = 79,230,185.11
5. Step 5: Solve for x
   x = 79,230,185.11/10,139.29
6. Step 6: Final answer
   x = 7,814.18