Finding the Fourth Proportional to 1,643.40, 2,460.15 and 1,276.56

Step by Step Solution

1. Step 1: Write the proportion equation
   1,643.40 : 2,460.15 = 1,276.56 : x
2. Step 2: Convert to fraction form
   1,643.40/2,460.15 = 1,276.56/x
3. Step 3: Cross multiply
   1,643.40x = 2,460.15 × 1,276.56
4. Step 4: Simplify right side
   1,643.40x = 3,140,529.08
5. Step 5: Solve for x
   x = 3,140,529.08/1,643.40
6. Step 6: Final answer
   x = 1,910.99