Finding the Fourth Proportional to 10,139.30, 13,992.09 and 5,663.12

Step by Step Solution

1. Step 1: Write the proportion equation
   10,139.30 : 13,992.09 = 5,663.12 : x
2. Step 2: Convert to fraction form
   10,139.30/13,992.09 = 5,663.12/x
3. Step 3: Cross multiply
   10,139.30x = 13,992.09 × 5,663.12
4. Step 4: Simplify right side
   10,139.30x = 79,238,814.76
5. Step 5: Solve for x
   x = 79,238,814.76/10,139.30
6. Step 6: Final answer
   x = 7,815.02