Finding the Fourth Proportional to 3,865.30, 5,792.72 and 2,820.40

Step by Step Solution

1. Step 1: Write the proportion equation
   3,865.30 : 5,792.72 = 2,820.40 : x
2. Step 2: Convert to fraction form
   3,865.30/5,792.72 = 2,820.40/x
3. Step 3: Cross multiply
   3,865.30x = 5,792.72 × 2,820.40
4. Step 4: Simplify right side
   3,865.30x = 16,337,780.06
5. Step 5: Solve for x
   x = 16,337,780.06/3,865.30
6. Step 6: Final answer
   x = 4,226.78