Finding the Fourth Proportional to 3,878.57, 5,779.32 and 3,690.28

Step by Step Solution

1. Step 1: Write the proportion equation
   3,878.57 : 5,779.32 = 3,690.28 : x
2. Step 2: Convert to fraction form
   3,878.57/5,779.32 = 3,690.28/x
3. Step 3: Cross multiply
   3,878.57x = 5,779.32 × 3,690.28
4. Step 4: Simplify right side
   3,878.57x = 21,327,309.01
5. Step 5: Solve for x
   x = 21,327,309.01/3,878.57
6. Step 6: Final answer
   x = 5,498.76