Finding the Fourth Proportional to 7,128.56, 9,837.50 and 3,984.80

Step by Step Solution

1. Step 1: Write the proportion equation
   7,128.56 : 9,837.50 = 3,984.80 : x
2. Step 2: Convert to fraction form
   7,128.56/9,837.50 = 3,984.80/x
3. Step 3: Cross multiply
   7,128.56x = 9,837.50 × 3,984.80
4. Step 4: Simplify right side
   7,128.56x = 39,200,470
5. Step 5: Solve for x
   x = 39,200,470/7,128.56
6. Step 6: Final answer
   x = 5,499.07