Finding the Fourth Proportional to 1,288.82, 1,778.96 and 784.86

Step by Step Solution

1. Step 1: Write the proportion equation
   1,288.82 : 1,778.96 = 784.86 : x
2. Step 2: Convert to fraction form
   1,288.82/1,778.96 = 784.86/x
3. Step 3: Cross multiply
   1,288.82x = 1,778.96 × 784.86
4. Step 4: Simplify right side
   1,288.82x = 1,396,234.55
5. Step 5: Solve for x
   x = 1,396,234.55/1,288.82
6. Step 6: Final answer
   x = 1,083.34