Finding the Fourth Proportional to 10,139.45, 13,992.43 and 5,663.20

Step by Step Solution

1. Step 1: Write the proportion equation
   10,139.45 : 13,992.43 = 5,663.20 : x
2. Step 2: Convert to fraction form
   10,139.45/13,992.43 = 5,663.20/x
3. Step 3: Cross multiply
   10,139.45x = 13,992.43 × 5,663.20
4. Step 4: Simplify right side
   10,139.45x = 79,241,929.58
5. Step 5: Solve for x
   x = 79,241,929.58/10,139.45
6. Step 6: Final answer
   x = 7,815.21