Finding the Fourth Proportional to 2,015.40, 2,780.73 and 1,269.30

Step by Step Solution

1. Step 1: Write the proportion equation
   2,015.40 : 2,780.73 = 1,269.30 : x
2. Step 2: Convert to fraction form
   2,015.40/2,780.73 = 1,269.30/x
3. Step 3: Cross multiply
   2,015.40x = 2,780.73 × 1,269.30
4. Step 4: Simplify right side
   2,015.40x = 3,529,580.59
5. Step 5: Solve for x
   x = 3,529,580.59/2,015.40
6. Step 6: Final answer
   x = 1,751.31