Finding the Fourth Proportional to 2,645.41, 3,937.88 and 2,605.99

Step by Step Solution

1. Step 1: Write the proportion equation
   2,645.41 : 3,937.88 = 2,605.99 : x
2. Step 2: Convert to fraction form
   2,645.41/3,937.88 = 2,605.99/x
3. Step 3: Cross multiply
   2,645.41x = 3,937.88 × 2,605.99
4. Step 4: Simplify right side
   2,645.41x = 10,262,079.95
5. Step 5: Solve for x
   x = 10,262,079.95/2,645.41
6. Step 6: Final answer
   x = 3,879.20