Finding the Fourth Proportional to 2,642.22, 3,964.81 and 1,821.15

Step by Step Solution

1. Step 1: Write the proportion equation
   2,642.22 : 3,964.81 = 1,821.15 : x
2. Step 2: Convert to fraction form
   2,642.22/3,964.81 = 1,821.15/x
3. Step 3: Cross multiply
   2,642.22x = 3,964.81 × 1,821.15
4. Step 4: Simplify right side
   2,642.22x = 7,220,513.73
5. Step 5: Solve for x
   x = 7,220,513.73/2,642.22
6. Step 6: Final answer
   x = 2,732.75