Finding the Fourth Proportional to 2,646.06, 3,969.82 and 1,328.21

Step by Step Solution

1. Step 1: Write the proportion equation
   2,646.06 : 3,969.82 = 1,328.21 : x
2. Step 2: Convert to fraction form
   2,646.06/3,969.82 = 1,328.21/x
3. Step 3: Cross multiply
   2,646.06x = 3,969.82 × 1,328.21
4. Step 4: Simplify right side
   2,646.06x = 5,272,754.62
5. Step 5: Solve for x
   x = 5,272,754.62/2,646.06
6. Step 6: Final answer
   x = 1,992.68