Finding the Fourth Proportional to 1,443.12, 1,991.28 and 822

Step by Step Solution

1. Step 1: Write the proportion equation
   1,443.12 : 1,991.28 = 822 : x
2. Step 2: Convert to fraction form
   1,443.12/1,991.28 = 822/x
3. Step 3: Cross multiply
   1,443.12x = 1,991.28 × 822
4. Step 4: Simplify right side
   1,443.12x = 1,636,832.16
5. Step 5: Solve for x
   x = 1,636,832.16/1,443.12
6. Step 6: Final answer
   x = 1,134.23