Finding the Fourth Proportional to 3,701.40, 5,106.72 and 2,639.31

Step by Step Solution

1. Step 1: Write the proportion equation
   3,701.40 : 5,106.72 = 2,639.31 : x
2. Step 2: Convert to fraction form
   3,701.40/5,106.72 = 2,639.31/x
3. Step 3: Cross multiply
   3,701.40x = 5,106.72 × 2,639.31
4. Step 4: Simplify right side
   3,701.40x = 13,478,217.16
5. Step 5: Solve for x
   x = 13,478,217.16/3,701.40
6. Step 6: Final answer
   x = 3,641.38