Finding the Fourth Proportional to 1,398.78, 1,930.29 and 769.33

Step by Step Solution

1. Step 1: Write the proportion equation
   1,398.78 : 1,930.29 = 769.33 : x
2. Step 2: Convert to fraction form
   1,398.78/1,930.29 = 769.33/x
3. Step 3: Cross multiply
   1,398.78x = 1,930.29 × 769.33
4. Step 4: Simplify right side
   1,398.78x = 1,485,030.01
5. Step 5: Solve for x
   x = 1,485,030.01/1,398.78
6. Step 6: Final answer
   x = 1,061.66