Finding the Fourth Proportional to 2,805.45, 3,878.52 and 2,105.61

Step by Step Solution

1. Step 1: Write the proportion equation
   2,805.45 : 3,878.52 = 2,105.61 : x
2. Step 2: Convert to fraction form
   2,805.45/3,878.52 = 2,105.61/x
3. Step 3: Cross multiply
   2,805.45x = 3,878.52 × 2,105.61
4. Step 4: Simplify right side
   2,805.45x = 8,166,650.50
5. Step 5: Solve for x
   x = 8,166,650.50/2,805.45
6. Step 6: Final answer
   x = 2,910.99