Finding the Fourth Proportional to 9,399.45, 12,970.76 and 5,420.33

Step by Step Solution

1. Step 1: Write the proportion equation
   9,399.45 : 12,970.76 = 5,420.33 : x
2. Step 2: Convert to fraction form
   9,399.45/12,970.76 = 5,420.33/x
3. Step 3: Cross multiply
   9,399.45x = 12,970.76 × 5,420.33
4. Step 4: Simplify right side
   9,399.45x = 70,305,799.55
5. Step 5: Solve for x
   x = 70,305,799.55/9,399.45
6. Step 6: Final answer
   x = 7,479.78