Finding the Fourth Proportional to 2,153.76, 2,972.16 and 1,222.32

Step by Step Solution

1. Step 1: Write the proportion equation
   2,153.76 : 2,972.16 = 1,222.32 : x
2. Step 2: Convert to fraction form
   2,153.76/2,972.16 = 1,222.32/x
3. Step 3: Cross multiply
   2,153.76x = 2,972.16 × 1,222.32
4. Step 4: Simplify right side
   2,153.76x = 3,632,930.61
5. Step 5: Solve for x
   x = 3,632,930.61/2,153.76
6. Step 6: Final answer
   x = 1,686.79