Finding the Fourth Proportional to 10,789.36, 16,148.40 and 7,620.64

Step by Step Solution

1. Step 1: Write the proportion equation
   10,789.36 : 16,148.40 = 7,620.64 : x
2. Step 2: Convert to fraction form
   10,789.36/16,148.40 = 7,620.64/x
3. Step 3: Cross multiply
   10,789.36x = 16,148.40 × 7,620.64
4. Step 4: Simplify right side
   10,789.36x = 123,061,142.98
5. Step 5: Solve for x
   x = 123,061,142.98/10,789.36
6. Step 6: Final answer
   x = 11,405.79