Finding the Fourth Proportional to 10,990.24, 16,490.72 and 5,145.76

Step by Step Solution

1. Step 1: Write the proportion equation
   10,990.24 : 16,490.72 = 5,145.76 : x
2. Step 2: Convert to fraction form
   10,990.24/16,490.72 = 5,145.76/x
3. Step 3: Cross multiply
   10,990.24x = 16,490.72 × 5,145.76
4. Step 4: Simplify right side
   10,990.24x = 84,857,287.35
5. Step 5: Solve for x
   x = 84,857,287.35/10,990.24
6. Step 6: Final answer
   x = 7,721.15