Finding the Fourth Proportional to 2,129.57, 2,939.01 and 1,290.48

Step by Step Solution

1. Step 1: Write the proportion equation
   2,129.57 : 2,939.01 = 1,290.48 : x
2. Step 2: Convert to fraction form
   2,129.57/2,939.01 = 1,290.48/x
3. Step 3: Cross multiply
   2,129.57x = 2,939.01 × 1,290.48
4. Step 4: Simplify right side
   2,129.57x = 3,792,733.62
5. Step 5: Solve for x
   x = 3,792,733.62/2,129.57
6. Step 6: Final answer
   x = 1,780.99