Finding the Fourth Proportional to 7,200.89, 9,936.84 and 3,970.61

Step by Step Solution

1. Step 1: Write the proportion equation
   7,200.89 : 9,936.84 = 3,970.61 : x
2. Step 2: Convert to fraction form
   7,200.89/9,936.84 = 3,970.61/x
3. Step 3: Cross multiply
   7,200.89x = 9,936.84 × 3,970.61
4. Step 4: Simplify right side
   7,200.89x = 39,455,266.59
5. Step 5: Solve for x
   x = 39,455,266.59/7,200.89
6. Step 6: Final answer
   x = 5,479.22