Finding the Fourth Proportional to 2,128.89, 2,936.46 and 1,289.85

Step by Step Solution

1. Step 1: Write the proportion equation
   2,128.89 : 2,936.46 = 1,289.85 : x
2. Step 2: Convert to fraction form
   2,128.89/2,936.46 = 1,289.85/x
3. Step 3: Cross multiply
   2,128.89x = 2,936.46 × 1,289.85
4. Step 4: Simplify right side
   2,128.89x = 3,787,592.93
5. Step 5: Solve for x
   x = 3,787,592.93/2,128.89
6. Step 6: Final answer
   x = 1,779.14