Finding the Fourth Proportional to 1,380.88, 1,905.72 and 791.44

Step by Step Solution

1. Step 1: Write the proportion equation
   1,380.88 : 1,905.72 = 791.44 : x
2. Step 2: Convert to fraction form
   1,380.88/1,905.72 = 791.44/x
3. Step 3: Cross multiply
   1,380.88x = 1,905.72 × 791.44
4. Step 4: Simplify right side
   1,380.88x = 1,508,263.04
5. Step 5: Solve for x
   x = 1,508,263.04/1,380.88
6. Step 6: Final answer
   x = 1,092.25