Finding the Fourth Proportional to 10,551.89, 14,628.20 and 9,990.10

Step by Step Solution

1. Step 1: Write the proportion equation
   10,551.89 : 14,628.20 = 9,990.10 : x
2. Step 2: Convert to fraction form
   10,551.89/14,628.20 = 9,990.10/x
3. Step 3: Cross multiply
   10,551.89x = 14,628.20 × 9,990.10
4. Step 4: Simplify right side
   10,551.89x = 146,137,094.30
5. Step 5: Solve for x
   x = 146,137,094.30/10,551.89
6. Step 6: Final answer
   x = 13,849.38