Finding the Fourth Proportional to 1,278.69, 1,764.57 and 719.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,278.69 : 1,764.57 = 719.15 : x
2. Step 2: Convert to fraction form
   1,278.69/1,764.57 = 719.15/x
3. Step 3: Cross multiply
   1,278.69x = 1,764.57 × 719.15
4. Step 4: Simplify right side
   1,278.69x = 1,268,990.52
5. Step 5: Solve for x
   x = 1,268,990.52/1,278.69
6. Step 6: Final answer
   x = 992.41