Finding the Fourth Proportional to 2,113.10, 3,171.68 and 1,805.30

Step by Step Solution

1. Step 1: Write the proportion equation
   2,113.10 : 3,171.68 = 1,805.30 : x
2. Step 2: Convert to fraction form
   2,113.10/3,171.68 = 1,805.30/x
3. Step 3: Cross multiply
   2,113.10x = 3,171.68 × 1,805.30
4. Step 4: Simplify right side
   2,113.10x = 5,725,833.90
5. Step 5: Solve for x
   x = 5,725,833.90/2,113.10
6. Step 6: Final answer
   x = 2,709.68