Finding the Fourth Proportional to 9,399.76, 12,942.12 and 7,637.20

Step by Step Solution

1. Step 1: Write the proportion equation
   9,399.76 : 12,942.12 = 7,637.20 : x
2. Step 2: Convert to fraction form
   9,399.76/12,942.12 = 7,637.20/x
3. Step 3: Cross multiply
   9,399.76x = 12,942.12 × 7,637.20
4. Step 4: Simplify right side
   9,399.76x = 98,841,558.86
5. Step 5: Solve for x
   x = 98,841,558.86/9,399.76
6. Step 6: Final answer
   x = 10,515.33