Finding the Fourth Proportional to 7,128.27, 9,836.82 and 3,985.07

Step by Step Solution

1. Step 1: Write the proportion equation
   7,128.27 : 9,836.82 = 3,985.07 : x
2. Step 2: Convert to fraction form
   7,128.27/9,836.82 = 3,985.07/x
3. Step 3: Cross multiply
   7,128.27x = 9,836.82 × 3,985.07
4. Step 4: Simplify right side
   7,128.27x = 39,200,367.09
5. Step 5: Solve for x
   x = 39,200,367.09/7,128.27
6. Step 6: Final answer
   x = 5,499.28