Finding the Fourth Proportional to 9,399.02, 12,971.16 and 5,420.30

Step by Step Solution

1. Step 1: Write the proportion equation
   9,399.02 : 12,971.16 = 5,420.30 : x
2. Step 2: Convert to fraction form
   9,399.02/12,971.16 = 5,420.30/x
3. Step 3: Cross multiply
   9,399.02x = 12,971.16 × 5,420.30
4. Step 4: Simplify right side
   9,399.02x = 70,307,551.45
5. Step 5: Solve for x
   x = 70,307,551.45/9,399.02
6. Step 6: Final answer
   x = 7,480.31