Finding the Fourth Proportional to 2,129.71, 2,939.27 and 1,290.41

Step by Step Solution

1. Step 1: Write the proportion equation
   2,129.71 : 2,939.27 = 1,290.41 : x
2. Step 2: Convert to fraction form
   2,129.71/2,939.27 = 1,290.41/x
3. Step 3: Cross multiply
   2,129.71x = 2,939.27 × 1,290.41
4. Step 4: Simplify right side
   2,129.71x = 3,792,857.71
5. Step 5: Solve for x
   x = 3,792,857.71/2,129.71
6. Step 6: Final answer
   x = 1,780.93