Finding the Fourth Proportional to 2,072.28, 3,109.62 and 1,911.90

Step by Step Solution

1. Step 1: Write the proportion equation
   2,072.28 : 3,109.62 = 1,911.90 : x
2. Step 2: Convert to fraction form
   2,072.28/3,109.62 = 1,911.90/x
3. Step 3: Cross multiply
   2,072.28x = 3,109.62 × 1,911.90
4. Step 4: Simplify right side
   2,072.28x = 5,945,282.48
5. Step 5: Solve for x
   x = 5,945,282.48/2,072.28
6. Step 6: Final answer
   x = 2,868.96