Finding the Fourth Proportional to 1,398.12, 1,929.18 and 838.51

Step by Step Solution

1. Step 1: Write the proportion equation
   1,398.12 : 1,929.18 = 838.51 : x
2. Step 2: Convert to fraction form
   1,398.12/1,929.18 = 838.51/x
3. Step 3: Cross multiply
   1,398.12x = 1,929.18 × 838.51
4. Step 4: Simplify right side
   1,398.12x = 1,617,636.72
5. Step 5: Solve for x
   x = 1,617,636.72/1,398.12
6. Step 6: Final answer
   x = 1,157.01