Finding the Fourth Proportional to 3,779.25, 5,215.41 and 2,100.78

Step by Step Solution

1. Step 1: Write the proportion equation
   3,779.25 : 5,215.41 = 2,100.78 : x
2. Step 2: Convert to fraction form
   3,779.25/5,215.41 = 2,100.78/x
3. Step 3: Cross multiply
   3,779.25x = 5,215.41 × 2,100.78
4. Step 4: Simplify right side
   3,779.25x = 10,956,429.02
5. Step 5: Solve for x
   x = 10,956,429.02/3,779.25
6. Step 6: Final answer
   x = 2,899.10