Finding the Fourth Proportional to 1,380.93, 1,902.72 and 938.06

Step by Step Solution

1. Step 1: Write the proportion equation
   1,380.93 : 1,902.72 = 938.06 : x
2. Step 2: Convert to fraction form
   1,380.93/1,902.72 = 938.06/x
3. Step 3: Cross multiply
   1,380.93x = 1,902.72 × 938.06
4. Step 4: Simplify right side
   1,380.93x = 1,784,869.45
5. Step 5: Solve for x
   x = 1,784,869.45/1,380.93
6. Step 6: Final answer
   x = 1,292.51