Finding the Fourth Proportional to 3,689.32, 5,085.84 and 2,639.56

Step by Step Solution

1. Step 1: Write the proportion equation
   3,689.32 : 5,085.84 = 2,639.56 : x
2. Step 2: Convert to fraction form
   3,689.32/5,085.84 = 2,639.56/x
3. Step 3: Cross multiply
   3,689.32x = 5,085.84 × 2,639.56
4. Step 4: Simplify right side
   3,689.32x = 13,424,379.83
5. Step 5: Solve for x
   x = 13,424,379.83/3,689.32
6. Step 6: Final answer
   x = 3,638.71