Finding the Fourth Proportional to 1,007.77, 1,392.06 and 789.46

Step by Step Solution

1. Step 1: Write the proportion equation
   1,007.77 : 1,392.06 = 789.46 : x
2. Step 2: Convert to fraction form
   1,007.77/1,392.06 = 789.46/x
3. Step 3: Cross multiply
   1,007.77x = 1,392.06 × 789.46
4. Step 4: Simplify right side
   1,007.77x = 1,098,975.69
5. Step 5: Solve for x
   x = 1,098,975.69/1,007.77
6. Step 6: Final answer
   x = 1,090.50