Finding the Fourth Proportional to 5,178.09, 7,145.79 and 2,820.25

Step by Step Solution

1. Step 1: Write the proportion equation
   5,178.09 : 7,145.79 = 2,820.25 : x
2. Step 2: Convert to fraction form
   5,178.09/7,145.79 = 2,820.25/x
3. Step 3: Cross multiply
   5,178.09x = 7,145.79 × 2,820.25
4. Step 4: Simplify right side
   5,178.09x = 20,152,912.60
5. Step 5: Solve for x
   x = 20,152,912.60/5,178.09
6. Step 6: Final answer
   x = 3,891.96