Finding the Fourth Proportional to 1,398.05, 1,928.75 and 838.53

Step by Step Solution

1. Step 1: Write the proportion equation
   1,398.05 : 1,928.75 = 838.53 : x
2. Step 2: Convert to fraction form
   1,398.05/1,928.75 = 838.53/x
3. Step 3: Cross multiply
   1,398.05x = 1,928.75 × 838.53
4. Step 4: Simplify right side
   1,398.05x = 1,617,310.54
5. Step 5: Solve for x
   x = 1,617,310.54/1,398.05
6. Step 6: Final answer
   x = 1,156.84