Finding the Fourth Proportional to 1,276.80, 1,761.48 and 834.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,276.80 : 1,761.48 = 834.72 : x
2. Step 2: Convert to fraction form
   1,276.80/1,761.48 = 834.72/x
3. Step 3: Cross multiply
   1,276.80x = 1,761.48 × 834.72
4. Step 4: Simplify right side
   1,276.80x = 1,470,342.59
5. Step 5: Solve for x
   x = 1,470,342.59/1,276.80
6. Step 6: Final answer
   x = 1,151.58