Finding the Fourth Proportional to 2,420.69, 3,635.89 and 2,115.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,420.69 : 3,635.89 = 2,115.72 : x
2. Step 2: Convert to fraction form
   2,420.69/3,635.89 = 2,115.72/x
3. Step 3: Cross multiply
   2,420.69x = 3,635.89 × 2,115.72
4. Step 4: Simplify right side
   2,420.69x = 7,692,519.90
5. Step 5: Solve for x
   x = 7,692,519.90/2,420.69
6. Step 6: Final answer
   x = 3,177.83