Finding the Fourth Proportional to 1,393.05, 2,086.89 and 774.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,393.05 : 2,086.89 = 774.89 : x
2. Step 2: Convert to fraction form
   1,393.05/2,086.89 = 774.89/x
3. Step 3: Cross multiply
   1,393.05x = 2,086.89 × 774.89
4. Step 4: Simplify right side
   1,393.05x = 1,617,104.68
5. Step 5: Solve for x
   x = 1,617,104.68/1,393.05
6. Step 6: Final answer
   x = 1,160.83