Finding the Fourth Proportional to 8,209.82, 11,296.72 and 7,980.18

Step by Step Solution

1. Step 1: Write the proportion equation
   8,209.82 : 11,296.72 = 7,980.18 : x
2. Step 2: Convert to fraction form
   8,209.82/11,296.72 = 7,980.18/x
3. Step 3: Cross multiply
   8,209.82x = 11,296.72 × 7,980.18
4. Step 4: Simplify right side
   8,209.82x = 90,149,859.01
5. Step 5: Solve for x
   x = 90,149,859.01/8,209.82
6. Step 6: Final answer
   x = 10,980.74