Finding the Fourth Proportional to 2,758.62, 3,808.72 and 2,128.05

Step by Step Solution

1. Step 1: Write the proportion equation
   2,758.62 : 3,808.72 = 2,128.05 : x
2. Step 2: Convert to fraction form
   2,758.62/3,808.72 = 2,128.05/x
3. Step 3: Cross multiply
   2,758.62x = 3,808.72 × 2,128.05
4. Step 4: Simplify right side
   2,758.62x = 8,105,159.55
5. Step 5: Solve for x
   x = 8,105,159.55/2,758.62
6. Step 6: Final answer
   x = 2,938.12