Finding the Fourth Proportional to 2,615.80, 3,609.83 and 1,420.80

Step by Step Solution

1. Step 1: Write the proportion equation
   2,615.80 : 3,609.83 = 1,420.80 : x
2. Step 2: Convert to fraction form
   2,615.80/3,609.83 = 1,420.80/x
3. Step 3: Cross multiply
   2,615.80x = 3,609.83 × 1,420.80
4. Step 4: Simplify right side
   2,615.80x = 5,128,821.31
5. Step 5: Solve for x
   x = 5,128,821.31/2,615.80
6. Step 6: Final answer
   x = 1,960.71