Finding the Fourth Proportional to 2,111.20, 3,164.10 and 1,868.20

Step by Step Solution

1. Step 1: Write the proportion equation
   2,111.20 : 3,164.10 = 1,868.20 : x
2. Step 2: Convert to fraction form
   2,111.20/3,164.10 = 1,868.20/x
3. Step 3: Cross multiply
   2,111.20x = 3,164.10 × 1,868.20
4. Step 4: Simplify right side
   2,111.20x = 5,911,171.62
5. Step 5: Solve for x
   x = 5,911,171.62/2,111.20
6. Step 6: Final answer
   x = 2,799.91