Finding the Fourth Proportional to 7,128.16, 9,835.89 and 3,984.55

Step by Step Solution

1. Step 1: Write the proportion equation
   7,128.16 : 9,835.89 = 3,984.55 : x
2. Step 2: Convert to fraction form
   7,128.16/9,835.89 = 3,984.55/x
3. Step 3: Cross multiply
   7,128.16x = 9,835.89 × 3,984.55
4. Step 4: Simplify right side
   7,128.16x = 39,191,595.50
5. Step 5: Solve for x
   x = 39,191,595.50/7,128.16
6. Step 6: Final answer
   x = 5,498.14