Finding the Fourth Proportional to 3,931.56, 5,426.86 and 2,605.40

Step by Step Solution

1. Step 1: Write the proportion equation
   3,931.56 : 5,426.86 = 2,605.40 : x
2. Step 2: Convert to fraction form
   3,931.56/5,426.86 = 2,605.40/x
3. Step 3: Cross multiply
   3,931.56x = 5,426.86 × 2,605.40
4. Step 4: Simplify right side
   3,931.56x = 14,139,141.04
5. Step 5: Solve for x
   x = 14,139,141.04/3,931.56
6. Step 6: Final answer
   x = 3,596.32