Finding the Fourth Proportional to 3,970.69, 5,478.30 and 2,644.61

Step by Step Solution

1. Step 1: Write the proportion equation
   3,970.69 : 5,478.30 = 2,644.61 : x
2. Step 2: Convert to fraction form
   3,970.69/5,478.30 = 2,644.61/x
3. Step 3: Cross multiply
   3,970.69x = 5,478.30 × 2,644.61
4. Step 4: Simplify right side
   3,970.69x = 14,487,939.57
5. Step 5: Solve for x
   x = 14,487,939.57/3,970.69
6. Step 6: Final answer
   x = 3,648.72