Finding the Fourth Proportional to 2,128.10, 2,936.84 and 1,288.62

Step by Step Solution

1. Step 1: Write the proportion equation
   2,128.10 : 2,936.84 = 1,288.62 : x
2. Step 2: Convert to fraction form
   2,128.10/2,936.84 = 1,288.62/x
3. Step 3: Cross multiply
   2,128.10x = 2,936.84 × 1,288.62
4. Step 4: Simplify right side
   2,128.10x = 3,784,470.76
5. Step 5: Solve for x
   x = 3,784,470.76/2,128.10
6. Step 6: Final answer
   x = 1,778.33