Finding the Fourth Proportional to 2,689.76, 4,036.82 and 1,391.60

Step by Step Solution

1. Step 1: Write the proportion equation
   2,689.76 : 4,036.82 = 1,391.60 : x
2. Step 2: Convert to fraction form
   2,689.76/4,036.82 = 1,391.60/x
3. Step 3: Cross multiply
   2,689.76x = 4,036.82 × 1,391.60
4. Step 4: Simplify right side
   2,689.76x = 5,617,638.71
5. Step 5: Solve for x
   x = 5,617,638.71/2,689.76
6. Step 6: Final answer
   x = 2,088.53