Finding the Fourth Proportional to 2,668.79, 4,002.89 and 721.15

Step by Step Solution

1. Step 1: Write the proportion equation
   2,668.79 : 4,002.89 = 721.15 : x
2. Step 2: Convert to fraction form
   2,668.79/4,002.89 = 721.15/x
3. Step 3: Cross multiply
   2,668.79x = 4,002.89 × 721.15
4. Step 4: Simplify right side
   2,668.79x = 2,886,670.51
5. Step 5: Solve for x
   x = 2,886,670.51/2,668.79
6. Step 6: Final answer
   x = 1,081.64