Finding the Fourth Proportional to 2,166.84, 2,989.98 and 1,222.56

Step by Step Solution

1. Step 1: Write the proportion equation
   2,166.84 : 2,989.98 = 1,222.56 : x
2. Step 2: Convert to fraction form
   2,166.84/2,989.98 = 1,222.56/x
3. Step 3: Cross multiply
   2,166.84x = 2,989.98 × 1,222.56
4. Step 4: Simplify right side
   2,166.84x = 3,655,429.95
5. Step 5: Solve for x
   x = 3,655,429.95/2,166.84
6. Step 6: Final answer
   x = 1,686.99