Finding the Fourth Proportional to 1,398.78, 1,943.69 and 1,383.59

Step by Step Solution

1. Step 1: Write the proportion equation
   1,398.78 : 1,943.69 = 1,383.59 : x
2. Step 2: Convert to fraction form
   1,398.78/1,943.69 = 1,383.59/x
3. Step 3: Cross multiply
   1,398.78x = 1,943.69 × 1,383.59
4. Step 4: Simplify right side
   1,398.78x = 2,689,253.41
5. Step 5: Solve for x
   x = 2,689,253.41/1,398.78
6. Step 6: Final answer
   x = 1,922.57