Finding the Fourth Proportional to 3,779.76, 5,215.67 and 2,100.90

Step by Step Solution

1. Step 1: Write the proportion equation
   3,779.76 : 5,215.67 = 2,100.90 : x
2. Step 2: Convert to fraction form
   3,779.76/5,215.67 = 2,100.90/x
3. Step 3: Cross multiply
   3,779.76x = 5,215.67 × 2,100.90
4. Step 4: Simplify right side
   3,779.76x = 10,957,568.12
5. Step 5: Solve for x
   x = 10,957,568.12/3,779.76
6. Step 6: Final answer
   x = 2,899.02