Finding the Fourth Proportional to 8,990.28, 12,415.14 and 8,499.42

Step by Step Solution

1. Step 1: Write the proportion equation
   8,990.28 : 12,415.14 = 8,499.42 : x
2. Step 2: Convert to fraction form
   8,990.28/12,415.14 = 8,499.42/x
3. Step 3: Cross multiply
   8,990.28x = 12,415.14 × 8,499.42
4. Step 4: Simplify right side
   8,990.28x = 105,521,489.22
5. Step 5: Solve for x
   x = 105,521,489.22/8,990.28
6. Step 6: Final answer
   x = 11,737.29