Finding the Fourth Proportional to 2,638.35, 3,960.50 and 1,665

Step by Step Solution

1. Step 1: Write the proportion equation
   2,638.35 : 3,960.50 = 1,665 : x
2. Step 2: Convert to fraction form
   2,638.35/3,960.50 = 1,665/x
3. Step 3: Cross multiply
   2,638.35x = 3,960.50 × 1,665
4. Step 4: Simplify right side
   2,638.35x = 6,594,224.18
5. Step 5: Solve for x
   x = 6,594,224.18/2,638.35
6. Step 6: Final answer
   x = 2,499.37