Finding the Fourth Proportional to 3,899.25, 5,382.59 and 2,780.37

Step by Step Solution

1. Step 1: Write the proportion equation
   3,899.25 : 5,382.59 = 2,780.37 : x
2. Step 2: Convert to fraction form
   3,899.25/5,382.59 = 2,780.37/x
3. Step 3: Cross multiply
   3,899.25x = 5,382.59 × 2,780.37
4. Step 4: Simplify right side
   3,899.25x = 14,965,577.86
5. Step 5: Solve for x
   x = 14,965,577.86/3,899.25
6. Step 6: Final answer
   x = 3,838.07