Finding the Fourth Proportional to 7,279.43, 10,919.20 and 3,990.72

Step by Step Solution

1. Step 1: Write the proportion equation
   7,279.43 : 10,919.20 = 3,990.72 : x
2. Step 2: Convert to fraction form
   7,279.43/10,919.20 = 3,990.72/x
3. Step 3: Cross multiply
   7,279.43x = 10,919.20 × 3,990.72
4. Step 4: Simplify right side
   7,279.43x = 43,575,469.82
5. Step 5: Solve for x
   x = 43,575,469.82/7,279.43
6. Step 6: Final answer
   x = 5,986.11