Finding the Fourth Proportional to 9,899.80, 13,650.42 and 7,909

Step by Step Solution

1. Step 1: Write the proportion equation
   9,899.80 : 13,650.42 = 7,909 : x
2. Step 2: Convert to fraction form
   9,899.80/13,650.42 = 7,909/x
3. Step 3: Cross multiply
   9,899.80x = 13,650.42 × 7,909
4. Step 4: Simplify right side
   9,899.80x = 107,961,171.78
5. Step 5: Solve for x
   x = 107,961,171.78/9,899.80
6. Step 6: Final answer
   x = 10,905.39