Finding the Fourth Proportional to 1,392.16, 2,086.86 and 776.14

Step by Step Solution

1. Step 1: Write the proportion equation
   1,392.16 : 2,086.86 = 776.14 : x
2. Step 2: Convert to fraction form
   1,392.16/2,086.86 = 776.14/x
3. Step 3: Cross multiply
   1,392.16x = 2,086.86 × 776.14
4. Step 4: Simplify right side
   1,392.16x = 1,619,695.52
5. Step 5: Solve for x
   x = 1,619,695.52/1,392.16
6. Step 6: Final answer
   x = 1,163.44