Finding the Fourth Proportional to 2,668.61, 4,003.56 and 819.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,668.61 : 4,003.56 = 819.72 : x
2. Step 2: Convert to fraction form
   2,668.61/4,003.56 = 819.72/x
3. Step 3: Cross multiply
   2,668.61x = 4,003.56 × 819.72
4. Step 4: Simplify right side
   2,668.61x = 3,281,798.20
5. Step 5: Solve for x
   x = 3,281,798.20/2,668.61
6. Step 6: Final answer
   x = 1,229.78