Finding the Fourth Proportional to 2,865.30, 4,289.55 and 2,138.10

Step by Step Solution

1. Step 1: Write the proportion equation
   2,865.30 : 4,289.55 = 2,138.10 : x
2. Step 2: Convert to fraction form
   2,865.30/4,289.55 = 2,138.10/x
3. Step 3: Cross multiply
   2,865.30x = 4,289.55 × 2,138.10
4. Step 4: Simplify right side
   2,865.30x = 9,171,486.86
5. Step 5: Solve for x
   x = 9,171,486.86/2,865.30
6. Step 6: Final answer
   x = 3,200.88