Finding the Fourth Proportional to 3,681.12, 5,080.16 and 2,109.20

Step by Step Solution

1. Step 1: Write the proportion equation
   3,681.12 : 5,080.16 = 2,109.20 : x
2. Step 2: Convert to fraction form
   3,681.12/5,080.16 = 2,109.20/x
3. Step 3: Cross multiply
   3,681.12x = 5,080.16 × 2,109.20
4. Step 4: Simplify right side
   3,681.12x = 10,715,073.47
5. Step 5: Solve for x
   x = 10,715,073.47/3,681.12
6. Step 6: Final answer
   x = 2,910.82