Finding the Fourth Proportional to 1,381.64, 1,906.37 and 822.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,381.64 : 1,906.37 = 822.31 : x
2. Step 2: Convert to fraction form
   1,381.64/1,906.37 = 822.31/x
3. Step 3: Cross multiply
   1,381.64x = 1,906.37 × 822.31
4. Step 4: Simplify right side
   1,381.64x = 1,567,626.13
5. Step 5: Solve for x
   x = 1,567,626.13/1,381.64
6. Step 6: Final answer
   x = 1,134.61