Finding the Fourth Proportional to 1,422.11, 1,963.73 and 891.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,422.11 : 1,963.73 = 891.89 : x
2. Step 2: Convert to fraction form
   1,422.11/1,963.73 = 891.89/x
3. Step 3: Cross multiply
   1,422.11x = 1,963.73 × 891.89
4. Step 4: Simplify right side
   1,422.11x = 1,751,422.23
5. Step 5: Solve for x
   x = 1,751,422.23/1,422.11
6. Step 6: Final answer
   x = 1,231.56