Finding the Fourth Proportional to 1,322.80, 1,821.31 and 1,123.21

Step by Step Solution

1. Step 1: Write the proportion equation
   1,322.80 : 1,821.31 = 1,123.21 : x
2. Step 2: Convert to fraction form
   1,322.80/1,821.31 = 1,123.21/x
3. Step 3: Cross multiply
   1,322.80x = 1,821.31 × 1,123.21
4. Step 4: Simplify right side
   1,322.80x = 2,045,718.79
5. Step 5: Solve for x
   x = 2,045,718.79/1,322.80
6. Step 6: Final answer
   x = 1,546.50