Finding the Fourth Proportional to 2,828.16, 3,899.52 and 2,620.80

Step by Step Solution

1. Step 1: Write the proportion equation
   2,828.16 : 3,899.52 = 2,620.80 : x
2. Step 2: Convert to fraction form
   2,828.16/3,899.52 = 2,620.80/x
3. Step 3: Cross multiply
   2,828.16x = 3,899.52 × 2,620.80
4. Step 4: Simplify right side
   2,828.16x = 10,219,862.02
5. Step 5: Solve for x
   x = 10,219,862.02/2,828.16
6. Step 6: Final answer
   x = 3,613.61