Finding the Fourth Proportional to 3,778.88, 5,215.68 and 2,100.86

Step by Step Solution

1. Step 1: Write the proportion equation
   3,778.88 : 5,215.68 = 2,100.86 : x
2. Step 2: Convert to fraction form
   3,778.88/5,215.68 = 2,100.86/x
3. Step 3: Cross multiply
   3,778.88x = 5,215.68 × 2,100.86
4. Step 4: Simplify right side
   3,778.88x = 10,957,376.90
5. Step 5: Solve for x
   x = 10,957,376.90/3,778.88
6. Step 6: Final answer
   x = 2,899.64