Finding the Fourth Proportional to 3,851.89, 5,315.15 and 2,173.20

Step by Step Solution

1. Step 1: Write the proportion equation
   3,851.89 : 5,315.15 = 2,173.20 : x
2. Step 2: Convert to fraction form
   3,851.89/5,315.15 = 2,173.20/x
3. Step 3: Cross multiply
   3,851.89x = 5,315.15 × 2,173.20
4. Step 4: Simplify right side
   3,851.89x = 11,550,883.98
5. Step 5: Solve for x
   x = 11,550,883.98/3,851.89
6. Step 6: Final answer
   x = 2,998.76