Finding the Fourth Proportional to 1,381.19, 1,905.89 and 791.60

Step by Step Solution

1. Step 1: Write the proportion equation
   1,381.19 : 1,905.89 = 791.60 : x
2. Step 2: Convert to fraction form
   1,381.19/1,905.89 = 791.60/x
3. Step 3: Cross multiply
   1,381.19x = 1,905.89 × 791.60
4. Step 4: Simplify right side
   1,381.19x = 1,508,689.04
5. Step 5: Solve for x
   x = 1,508,689.04/1,381.19
6. Step 6: Final answer
   x = 1,092.31