Finding the Fourth Proportional to 1,381.31, 1,906.11 and 783.93

Step by Step Solution

1. Step 1: Write the proportion equation
   1,381.31 : 1,906.11 = 783.93 : x
2. Step 2: Convert to fraction form
   1,381.31/1,906.11 = 783.93/x
3. Step 3: Cross multiply
   1,381.31x = 1,906.11 × 783.93
4. Step 4: Simplify right side
   1,381.31x = 1,494,253.87
5. Step 5: Solve for x
   x = 1,494,253.87/1,381.31
6. Step 6: Final answer
   x = 1,081.77