Finding the Fourth Proportional to 2,166.88, 2,990.16 and 1,222.82

Step by Step Solution

1. Step 1: Write the proportion equation
   2,166.88 : 2,990.16 = 1,222.82 : x
2. Step 2: Convert to fraction form
   2,166.88/2,990.16 = 1,222.82/x
3. Step 3: Cross multiply
   2,166.88x = 2,990.16 × 1,222.82
4. Step 4: Simplify right side
   2,166.88x = 3,656,427.45
5. Step 5: Solve for x
   x = 3,656,427.45/2,166.88
6. Step 6: Final answer
   x = 1,687.42