Finding the Fourth Proportional to 1,398.01, 1,929.68 and 838.57

Step by Step Solution

1. Step 1: Write the proportion equation
   1,398.01 : 1,929.68 = 838.57 : x
2. Step 2: Convert to fraction form
   1,398.01/1,929.68 = 838.57/x
3. Step 3: Cross multiply
   1,398.01x = 1,929.68 × 838.57
4. Step 4: Simplify right side
   1,398.01x = 1,618,171.76
5. Step 5: Solve for x
   x = 1,618,171.76/1,398.01
6. Step 6: Final answer
   x = 1,157.48