Finding the Fourth Proportional to 1,381.14, 1,906.20 and 938.79

Step by Step Solution

1. Step 1: Write the proportion equation
   1,381.14 : 1,906.20 = 938.79 : x
2. Step 2: Convert to fraction form
   1,381.14/1,906.20 = 938.79/x
3. Step 3: Cross multiply
   1,381.14x = 1,906.20 × 938.79
4. Step 4: Simplify right side
   1,381.14x = 1,789,521.50
5. Step 5: Solve for x
   x = 1,789,521.50/1,381.14
6. Step 6: Final answer
   x = 1,295.68