Finding the Fourth Proportional to 3,920.67, 5,402.72 and 2,798.45

Step by Step Solution

1. Step 1: Write the proportion equation
   3,920.67 : 5,402.72 = 2,798.45 : x
2. Step 2: Convert to fraction form
   3,920.67/5,402.72 = 2,798.45/x
3. Step 3: Cross multiply
   3,920.67x = 5,402.72 × 2,798.45
4. Step 4: Simplify right side
   3,920.67x = 15,119,200.78
5. Step 5: Solve for x
   x = 15,119,200.78/3,920.67
6. Step 6: Final answer
   x = 3,856.28