Finding the Fourth Proportional to 2,153.81, 2,972.27 and 1,222.31

Step by Step Solution

1. Step 1: Write the proportion equation
   2,153.81 : 2,972.27 = 1,222.31 : x
2. Step 2: Convert to fraction form
   2,153.81/2,972.27 = 1,222.31/x
3. Step 3: Cross multiply
   2,153.81x = 2,972.27 × 1,222.31
4. Step 4: Simplify right side
   2,153.81x = 3,633,045.83
5. Step 5: Solve for x
   x = 3,633,045.83/2,153.81
6. Step 6: Final answer
   x = 1,686.80