Finding the Fourth Proportional to 2,821.59, 3,889.72 and 1,979.67

Step by Step Solution

1. Step 1: Write the proportion equation
   2,821.59 : 3,889.72 = 1,979.67 : x
2. Step 2: Convert to fraction form
   2,821.59/3,889.72 = 1,979.67/x
3. Step 3: Cross multiply
   2,821.59x = 3,889.72 × 1,979.67
4. Step 4: Simplify right side
   2,821.59x = 7,700,361.99
5. Step 5: Solve for x
   x = 7,700,361.99/2,821.59
6. Step 6: Final answer
   x = 2,729.09