Finding the Fourth Proportional to 1,398.06, 1,929.39 and 838.56

Step by Step Solution

1. Step 1: Write the proportion equation
   1,398.06 : 1,929.39 = 838.56 : x
2. Step 2: Convert to fraction form
   1,398.06/1,929.39 = 838.56/x
3. Step 3: Cross multiply
   1,398.06x = 1,929.39 × 838.56
4. Step 4: Simplify right side
   1,398.06x = 1,617,909.28
5. Step 5: Solve for x
   x = 1,617,909.28/1,398.06
6. Step 6: Final answer
   x = 1,157.25